Glossary Word Description
3X1 A ratio used to describe an alternative twill weave (see "Twill").
501 The lot number used for the iconic Levi’s jeans cut. In 1890, Levi Strauss & Co assigned the 501 lot number to their famous patented copper-riveted jeans. The straight fit 501 remains relatively unchanged in cut and aesthetic, although a number of iterations have existed through the years, the rise and leg width changing in accordance with trends and manufacturing techniques. Used as a blueprint by a number of Japanese denim brands, Iron Heart’s 634 and 1955 cuts are both inspired by 501 iterations from the mid to late 20th century.
5-Pocket Jeans The standard number of pockets found on a pair of jeans, introduced in 1922 by Levis Strauss & Co. 5-pocket jeans include two back pockets, two front pockets, and a coin (or watch) pocket, typically found in and above the right-hand front pocket. Contrary to popular belief, the fifth pocket is in fact one of the two back pockets, which was introduced in 1905 (the coin pocket appeared in 1890).
Arc See 'Arcuate'
Arcuate Arcuates or Arcs refers to the decorative stitching on the back pockets of jeans. Levi Strauss & Co have been credited as inventing this feature for the 501 jeans, with a batwing design in double stitching. Arcuates have been used to differentiate jeans brands ever since. Levi’s arctuates were one of the jeans features referenced in lawsuits brought by Levi’s against Japanese jean manufactures, including Iron Heart. These lawsuits sought to protect trademarks to prevent competitor imitation, particularly in America, where no other denim brands are allowed to use patterns that remotely resemble Levi's arcs.
Aspero Aspero is a naturally occurring wild cotton that is found in the foothills of North East Peru, and being a tree, is not farmed, and so is one of the purest most organic cotton available. As it cannot be mass-produced, it has been highly prized for generations by the indigenous Peruvian population for its qualities of fineness, softness, volume, and also strength. Iron Heart use Aspero cotton in their famous Ultra Heavy Flannel (UHF) shirts (eg. IHSH-232).
Atari A Japanese term for denim that has faded well in all the right areas, such as on the thigh, the back of the knees, along the ridges of the seams, on the back yoke, pockets, belt loops and fly. In other all the areas that a well worn pair of jeans generally show fading.
Back Cinch A fabric strap and buckle that is situated on the back of the jeans, jackets or vests to tighten the waistband. Jeans with a back cinch are also referred to as 'buckle back'. In most part, jeans makers abandoned the back cinch in 1942. The back cinch has been re-introduced by some vintage, heritage inspired brands. Iron Heart use the back cinch on their work vests (eg. The IHV-02-IND), and occasionally on jackets.
Back Patch See 'Jacron'.
Back Pocket Flasher A fabric, paper, or cardboard flap attached to the right back pocket. Traditionally used to provide information about the jeans, such as sizing, fabric weights, and cuts. The flasher is also used as a marketing tool, featuring illustrations or graphics that represent the jeans' brand.
Baggy Over-sized wide-leg jeans worn low on the waist. Popular in the 1990s amongst skateboarders and the hip-hop community.
Bar Tacks A band of closely spaced stitches positioned to reinforce and strengthen potential stress points in a garment, such as belt loops, zippers, and pocket openings.
Bell-bottoms Hugely popular in the 1960s and 70s, bell-bottom pants have a tight waist and thigh with legs that become much wider below the knee, producing a silhouette that vaguely resembles the shape of a bell. Initially designed for sailors, the wide legs made them easy to roll up, avoiding wet decks.
Belt Loops Belt-loops - Fabric loops that have been positioned around the waistband to hold a belt. Belt loops started to replace suspender buttons in the 1920s, once the belt trend emerged after World War I. With the exception of some early iterations of the 634 cut, Iron Heart sew the belt loops under and into the waistband of their 5-pocket jeans for increased strength and a cleaner aesthetic.
Belt Loops Sewn Into Waist Band Belt loops sewn into waist band for added strength
Big E Before 1971, Levis Strauss & Co jeans and jackets featured a red label that included an embroidered uppercase 'E', spelling 'LEvis'. After 1971, their red label started to use a lowercase 'e', making any items with a big 'E' much rarer and highly sought after by collectors.
Bleeding Unlike 'crocking', bleeding occurs when a fabric dye comes into contact with liquid and transfers on to something else, such as another fabric or skin.
Blue Bell The Blue Bell Overall Company first produced wrangler Jeans in 1947. Founded in 1904, making denim overalls, they started producing jeans after World War II.
Blue Jeans The name given to trousers that are made of blue denim. Traditionally, indigo dye is used to give jeans their deep blue colour.
Boll A round and fluffy seed capsule found on plants such as cotton or flax. For cotton, the boll fibers are used to produce the cotton fabric.
Bootcut Similar to bell-bottoms but less extreme and much slimmer in silhouette. Designed with a leg opening that will easily fit over a large pair of boots. 
Bootleg See 'Bootcut'
Boyfriend A generally baggier cut of women's jeans that are looser around the thigh, in comparison to a more traditional fit. As the name implies, these jeans are a little more casual and fit as though they may have been borrowed from a male friend.
Broken Twill A denim weave where the twill line changes direction at every two warp ends, canceling out the notorious leg twisting effect usually found with regular Left Hand Twill (LHT) or Right Hand Twill (RHT) denim jeans. 
Buckle Back See 'Back Cinch'
Buffalo Check Buffalo Check - Buffalo check (plaid) is an even check consisting of two alternating colour stripes, one dark and one light, at right angles, thus forming a checked pattern of even squares. Buffalo Check was first used by Iron Heart in 2007 on the IHSH-06, and later on the first ever 12oz UHF IHSH-20. It has been a staple pattern for Iron Heart, used on many UHF iterations since the IHSH-20 and currently features on the first ever UHF in continuous production (IHSH-232).
Button A round fastener, typically made of a metal alloy such as brass, copper, or aluminum, and used to fasten two pieces of fabric together. They are usually built from two components: a short nail that is attached to the fabric, and 'the head', which is used to connect the separate fabrics via a buttonhole.
Button Fly Button Fly - The opening at the front of a pair of trousers with buttons. First introduced in 1873 by Levi Strauss & Co, the riveted button fly has been seen on jeans since the original 501. The zipper fly wasn't introduced until 20 years later. The majority of Iron Heart jeans use the button fly with the exception of those jeans with “Z” in the lot number (eg. IH-634Z) 
Buttonhole A hole that a button is pushed through to fasten two pieces of fabric together.
Carding The mechanical process that passes fibers through wire teeth to untangle, clean, and mix them to produce a continuous web (or 'silver') suitable for processing. This method is generally used to create woolen threads and is relatively similar to the combing method. See 'Combing'.
Carrot Fit A cut similar to skinny jeans, but with a loose and low-hanging crotch. Named after resembling the shape of a carrot: wide at the top and narrow at the bottom. Also known as peg pants.
Cast/Caste In reference to additional colour tones that are present in the fabric, as a result of being added during the denim dyeing process. Depending on the method and dye used, denim can have a green, red, yellow, black, brown, or grey cast to it.
Chain Stitching Chain Stitching - A series of looped stitches from one piece of thread, looping back on itself to create a chain-like link. Traditionally used to hem jeans, the chain stitching allows the hem to twist and roll after washing, causing some well-loved fading known as 'roping'. The earliest evidence of chain stitching dates from 1100 BC in China. At Iron Heart our jeans come with hems chainstitched from the factory. Iron Heart International offers hemming and will recreate the chainstitching on jeans we hem, both at point of sale and aftermarket, using one of our vintage Union Special machines.
Chambray Chambray, also known as chambric, is a plain weave fabric woven with a coloured yarn in the warp and a white yarn in the weft. The chambray’s warp and weft threads will alternate one over the other, and typically, the underside of chambray will appear much more similar to its face side. Iron Heart have used chambray in their shirting since the beginning, the IHSH-05 being their first chambray shirt. Since then the material has featured regularly in seasonal collections and on the ever present classics, the IHSH-13 and IHSH-21.
Chino Chino cloth is a twill fabric, originally made of 100% cotton. Developed in the mid-19th century for British and French military uniforms, it has since migrated into civilian wear. Trousers made from chino gained popularity in the U.S. when Spanish–American War veterans returned from the Philippines with their twill military trousers. The etymology of the term chino is disputed. Some sources identify the root as the American Spanish language word chino, which translated, literally means toasted. Because the cloth itself was originally manufactured in China, the name of the trousers may have come from the country of origin. First designed to be used in the military and then taken up by civilians, chino fabric was originally made to be simple, hard-wearing and comfortable for soldiers to wear; the use of natural earth-tone colors also began the move towards camouflage, instead of the brightly colored tunics used prior. Iron Heart Chino pants reference both the fabric’s military and civilian heritage, and come in a variety of cuts. In addition the material is often used for shirting in our seasonal collections.   
Cigarette A slim cut with a high rise and straight legs from knee to hem that stops at the ankle. Popular amongst women in the 1950s.
Coin Pocket Originally designed for cowboys in the 1800s as a place to store and protect their pocket watches. Throughout its history, this small pouch has been given many titles and uses, including the Coin Pocket. It is a common mistake to consider the coin pocket the “fifth” pocket on 5-pocket jeans. In fact the coin pocket pre-dates the use of two back pockets.
Colourfast The level of bonding, attachment, or fastening that a dye has with a fabric. Indigo is well known for its colourfastness with denim, although colour loss often occurs with exposure to sunlight and water.
Combing Combing is the primary preparation process that separates and untangles the cotton fibers before they are spun into yarn. This is achieved by passing the fibers through a series of straight metal teeth, placing them into long parallel lines, and filtering out shorter lengthed fibers to increase the fabric's thread count. Combing is used to produce finer, stronger, cleaner, and more lustrous fibers than the 'carding' method, a similar technique for preparing cotton. See 'Carding'
Combs See 'Honeycombs'.
Cone Mills Once a world leader in the textile manufacturing of cotton fabrics, such as corduroy, flannel, and denim. Founded in 1885, this Greensboro, North Carolina, USA, based mill became the primary supplier of Levi Strauss & Co in 1910, and the exclusive supplier of denim for the 501 jean. Sadly, Cone Mills Corporation ceased operations in 2004 due to bankruptcy, and the White Oak plant ceased producing Cone Denim in 2017.
Copper Rivet See 'Rivet'.
Cordovan Cordovan (or shell cordovan) is a type of leather commonly used in high-end shoemaking. Cordovan is an equine leather made from the fibrous flat muscle beneath the hide on the rump of the horse. The leather derives its name from the city of Cordoba, Spain, where it was first practiced by the Visigoths in the seventh century, and later also by the Moors. It is called "shell" because the shape of the tanned leather resembles an open shell. It is a difficult and expensive leather to make, and in the late 19th and early 20th century was mostly used for razor strops to sharpen razors in barbershops. More recently, it has been increasingly used for shoes, wallets, and watch straps due to its aesthetic qualities and exceptional durability and unique non-creasing characteristic. Iron Heart produce a number of premium items using Cordovan leather including the superlative IHG-01 and IHG-02 wallets.
Corduroy Corduroy is a textile composed of twisted fibers that, when woven, lie parallel (similar to twill) to one another to form the cloth's distinct pattern, a "cord." Modern corduroy is most commonly composed of tufted cords, sometimes exhibiting a channel (bare to the base fabric) between the tufts. Corduroy is, in essence, a ridged form of velvet. The fabric looks as if it is made from multiple cords laid parallel to each other and then stitched together. The word corduroy is from cord and duroy, a coarse woolen cloth made in England in the 18th century. As a fabric, corduroy is considered a durable cloth. Corduroy is found in the construction of trousers, jackets, and shirts. The width of the cord is commonly referred to as the size of the "wale" (see ‘wale’). 
Cotton Cotton is a natural textile derived from the seed-hair fiber of the Gossypium (cotton plant/tree) and is one of the world's largest agricultural crops, noted for it's economic and bountiful yield, which is able to grow in tropical and subtropical regions around the world. In its natural state, cotton is a soft and fluffy staple fiber that grows in a boll, which forms a protective case around the cotton plant's seeds. Once harvested, the cotton fibers are baled, ginned, cleaned, carded, drawn, and combed, ready for roving before they are finely spun into yarn. The oldest cotton fabric has been dated to 6000 BC, which is about 7000 years old. Today, around 75% of menswear contains some kind of cotton blend, compared to 60% of womenswear.
Cotton Drill Cotton drill is a versatile and very durable utility fabric with a strong diagonal twill weave. Made with coarse carded yarns, it is a popular choice for uniforms from military to safari. Cotton drill makes an occasional appearance in Iron Hearts seasonal collections.
Cotton Duck Cotton duck (from Dutch doek, ’linen canvas’), also simply duck, sometimes duck cloth or duck canvas, is  commonly called ‘canvas’ outside the textile industry, is a heavy, plain woven cotton fabric. Canvas differs from other heavy cotton fabrics, such as denim, in being plain weave rather than twill weave. Canvas comes in two basic types: plain and duck. The threads in duck canvas are more tightly woven. Iron Heart use duck canvas in most of their clothing lines. From bottoms, vests and shirting, to jackets, with the ever present IH-666D being a famous example. 
Cotton-boll See 'Boll'
CPO Issued to Chief Petty Officers of the US Navy since the 1930’s, the CPO shirt was originally a shirt/jacket hybrid, made of navy dyed wool. Designed as an easily removable cold weather layer for servicemen, the CPO became a post-war civilian menswear staple due to its practical qualities and versatility.

At Iron Heart, our CPO’s retain the functionality of the original military overshirt, then dial it up by adding handwarmer pockets and effective, secure, snap closure. The cut is more fitted, references western styling, but just like the originals, they are built like a battleship to protect you from the elements. Available in a variety of fabrics, lined and unlined. 
Crocking Unlike 'bleeding', crocking occurs when the (dry) excess dye is physically rubbed off of one fabric and transferred on to something else, such as another fabric or skin.
Crotch Rivet Crotch rivets were designed to reinforce and strengthen the fly and were commonplace on Levi Strauss & Co blue jeans from 1873 until 1939, when changes we’re made to conserve raw materials in line with the new rules set by the War Production Board during World War II.
Cut The design and shape of a pair of jeans. The cut determines how the jeans will look and fit the body. From how tall the rise is, to the taper on the leg. Straight, Skinny, Bootcut and Flare are some examples of jeans cut.

Iron Heart’s first cut was the omnipresent 634, which Haraki-san designed and refined many times before it first saw the light of day. Based on a mid-century 634 cut, it has a medium rise and a regular, straight leg. While resisting the temptation to follow trends and release a continual stream of new designs, our family of cuts has grown over the years to include a range of straight, tapered, regular and slim cuts with a variety of rises, to cater for all tastes. (link?)
Denim Denim is a durable, rigid, and often coarse twilled fabric, usually woven from cotton using a colour-dyed warp and ecru (natural) weft. The weight of denim is determined by its heaviness across one square yard of fabric, meaning that a square yard of 21oz denim weighs 21 ounces. Named after Nîmes, a French city that is famous for its textiles, denim was originally called "serge de Nîmes", meaning "serge from Nîmes". Because the "s" is not pronounced in french, the name was understood as "serge de Nîm" or "serge denim" in english, eventually shortened to denim.
Denim Head A description used to describe a denim enthusiast.
Density Density refers to the difference between a looser or tighter weave of denim fabric and the number of yarns that are used to make up that weave. The higher the density, the sturdier the denim.

At Iron Heart we offer a range of densities in our denim. The now defunct UHR is famously dense after soaking, whereas the flagship 21oz denim offers a much looser weave despite the heaviness of the fabric, thus allowing for the jeans to be worn comfortably in warmer temperatures.
Dip Dye Dip dyeing is the process of dipping fabric or yarn into a dye. The more dips, the deeper and darker the dye's colour transfer will be on to the fabric or yarn.
Discharge Printed Discharge Printed - Discharge printing, also called Extract Printing, is a method of applying a design to dyed fabric by printing a colour-destroying agent, such as chlorine or hydrosulfite, to bleach out a white or light pattern on the darker coloured ground. Iron Heart use this to great effect in the production of their indigo and black wabash fabrics (see ‘wabash’). The 12oz IHSH-62 and IHSH-68 are beautiful examples of this proprietary fabric, while a 21oz version was created in 2018 (IH-825).
Dobby Dobby is a woven fabric produced on a dobby loom, characterised by small geometric patterns and extra texture in the cloth.  The warp and weft threads may be the same colour or different.
Donut Button Donut Buttons - A staple of denim wear and an important part of jeans hardware, the donut button is a non-swivel fixed metal button with a hollow centre. The fact that it uses less metal means the button is slightly lighter and it was a popular choice during the World War II rationing period. It is used on all Iron Heart button fly jeans, and a variety of denim jackets, vests and other trousers. The Iron Heart donut button comes in a variety of metals depending on the aesthetic of the garment and is branded “Iron Heart Works Inc”.
Double Needle Stitch A double needle (or twin needle) is a needle with a single shank and two shafts that stitch two parallel seams in a continuous line. Double stitching is a widespread technique in jeans making, used to reinforce hems, pocket fixings, and many other parts of a jean that requires strengthening.
Drawing/Drafting Drawing, or drafting, is a process in which the cotton fibers are passed through a series of rollers, which stretches, straightens and aligns them. In total, the fiber is elongated to six or eight times its original length, transforming them into string-like "drawn-sliver". 
Drill See 'Cotton Drill'.
Dry Denim Simply put, dry denim jeans are jeans that have been made with denim that has not gone through the pre-wash process. Because of this, dry denim jeans can feel rough and rigid when worn for the first time and it can take a little while to 'break them in' and soften them up. The term should be seen as being synonymous with "raw" and "loomstate". However the term is often used, perhaps incorrectly, for either all selvedge jeans, or any denim that has not had post wash processing, or finishing and retains an even indigo colour.
Dual Ring-Spun Dual ring-spun, or 'ring-ring' denim, is a denim weave in which both the warp and weft are made using ring-spun yarn. A yarn type that is created by rolling the fibers into shape, rather than pressing them. Compared to open-end and regular ring-spun denim, dual ring-spun denim has a much softer hand feel.
Duck See 'Cotton Duck'.
Dungarees Originally, "dungaree" was a type of coarse cloth which dates back to the 17th century, thought to be named after the Indian village 'Dongari Kapar' in the region of Bombay. The Hindi name for the cloth was 'Dungri', and was exported to England to produce cheap and highly durable workwear during the 1600s. Over this time, the original name received an additional syllable, becoming "dungaree". It wasn't until 1853 that the fabric was used by Levi Strauss & Co to produce a bibbed trouser, which we now recognise as overalls.
Dyeing Dyeing is the process of tinting and adding colour to the (warp) yarn. This is achieved by dipping and soaking the yarn into a dye liquid. In denim making, indigo dye is usually used - a dye that turns blue during oxidization, or 'airing'. In between yarn dips and soaking, the indigo is exposed to air, which turns it from yellow, to green, to blue. The more dips the yarn receives, the deeper the final colour will be. At the end of the dyeing process, yarns are sometimes rinsed to remove any excess dye.
Eco-Denim A term for denim that has been produced using environmentally friendly, sustainable and or recycling techniques. This can be achieved in a number of ways, such as using organic cotton or recycled cutting room floor fibers to make jeans, or even filtering and re-using indigo dye-stuffs. Eco-denim works towards creating a greener future for the denim industry, reducing the impact on the environment. Iron Heart’s 14.7oz Eco denim uses the a combination of techniques to lessen its carbon footprint, and is available in various jean cuts, the IHSH-252 CPO, as well as future planned products.
Ecru Ecru is the natural off-white colour of undyed cotton yarn. More recently the term has been used to refer to any off white colour, natural or otherwise.
Elastane Formerly known as 'Fiber K'. Invented by Dupont textile scientist Joseph C. Shivers in 1958 to replace rubber in garments, elastane is a synthetic fiber known for its incredible elasticity and ability to withstand high temperatures. Dupont chose the trade name "Lycra" to distinguish its brand of spandex fibers (spandex is an anagram of 'expands'). Quite often, elastane is the fiber that provides the comfortable stretch in stretch-jeans. See also 'Strech-Denim'.
Embroidery Embroidery is a technique of decorating cloth with patterns and details that are sewn with a needle and thread.
Faded Denim Denim fading occurs as a result of pigment dye being removed through heavy wear and/or washing. The abrasion these two actions causes, means that over time the indigo (or any other pigment dye), is removed, revealing the natural colour from the core of the cotton yarn. In some instances, brands artificially fade their denim products through various "finishing" methods, such as stone washing, hand sanding, and even lasering.
Fair to Middling A term that originally referred to graduations of quality in cotton. Cotton is graded according to its physical characteristics such as staple length, strength, colour, fineness, smoothness, and uniformity. This term represents an average grade of cotton.
Felled Seam/Felled Seams Felled seam, or flat-fell seam, is a seam made by placing one edge inside a folded edge of fabric, then stitching the fold down. It includes a topstitched finish. It is useful for keeping seam allowances flat and covering raw edges. It is considered a superior finish both structurally and aesthetically and is widely used across Iron Heart’s range of clothing.
Finishing A term referring to either one of two processes. 1) the final step in denim production, such as burning off loose fibers from a roll of denim, or 2) artificial fading methods used to visually age a pair of jeans, such as stone washing.
Fit In reference to the overall design of the jeans, regarding the shape and how they fit the body. See 'Cut'.
Five Pocket Jeans See '5-pocket Jeans'.
Flag See 'Tab'.
Flare Inspired by bell-bottoms, the flared jean was a brainchild of the 1960s counter-culture movement in the USA, where personalized denim was born. Flares were initially created by splitting the seams of straight-legged jeans and widening the leg openings by sewing fabric panels in them. This improvised silhouette became an official cut once denim brands started to recreate and sell replicas.
Flasher See 'Back Pocket Flasher'
Fustian A heavy cloth woven with a linen warp and a cotton weft originating from the medieval times, possibly named after Fustat, the Egyptian city near Cairo. Chiefly used for menswear, although it was often used for padding, which garnered the term 'fustian' meaning 'padded out' or purposeless words.
Garment Dyed Garment dyeing is the process of dyeing a fully finished garment. The garments are dipped into a coloured dye vat as a whole. Garment dyeing creates a unique all-over colour that can slightly vary from garment to garment. Clothing which uses this technique is often distinguishable from those that have used a conventional dye technique, as the labels and lining become the same colour as the rest of the garment. Iron Heart’s overdyed clothing is an excellent example of this (IHSH-178, IH-888S-OD)
Ginning The process of removing cotton seeds from harvested cotton fiber, using a Cotton Gin, a machine invented in 1794 by Eli Whitney. Ginning ribs pull the fibers from the seeds, and the separated seeds are cleaned reviewed for re-planting.
Glen Check Glen check or glen plaid is derived from Glenurquhart in Scotland, where the New Zealand-born Countess of Seafield, Nina Caroline Ogilvie-Grant, had the design developed to use for her gamekeeper’s outfits in the early 19th Century. The pattern came to true popularity when Edward VIII, as Prince of Wales, visited the Seafield estate to hunt and took a fancy to the design, having some cloth created for himself in brown and cream - hence it’s other name, the Prince of Wales check.
While Prince of Wales checks have generally become smaller and finer over time, the term glen check today tends to refer to designs of a larger scale, in keeping with the original Scottish pattern. 
Gold Rush The movement that inspired the blue jeans. In 1848, around 300,000 people migrated to California in search of gold, after James W. Marshall found gold on his land at Sutter's Mill in Coloma. Inspired by this new development, Loeb Strauss (later Levis Strauss) created a pair of jeans that would accommodate the demand for durable pants, establishing his business and jeans brand in the history books.
Good to Middling A term for the highest grade of cotton, represented by the letters 'GM'. Good to Middling cotton has an off-white, creamy colour and contains virtually no foreign matter.
Green Cast Denim that is dyed with a green sulphur dye before it is dyed with indigo. Once dyed with indigo, green cast denim will have a slight green tone to its appearance. When the denim fades, shades of bluey-greens will start to show.
Grey Cast Denim that is dyed with a grey sulphur dye before it is dyed with indigo. Once dyed with indigo, grey cast denim will have a slight grey tone to its appearance. When the denim fades, shades of grey will start to show.
Hand Hand (or “Handle”), is a term used to describe the aggregate of a fabric’s tactile qualities, such as it’s thickness and softness. In denim terms this could refer to how smooth or rough, crunchy or supple, heavy or light, slubby or even, dense or loose the denim is. The hand of Iron Heart’s 21oz denim is much softer, more supple, and looser, than than the hand of the 25 oz denim.
Handle See 'Hand'.
Hangtag A tag that hangs from the garment which includes product information and any other desired marketing communications. A similar tool to the back pocket flasher.
Hank Dyeing Hank dyeing, or 'skein dyeing', is a dyeing process that maximises the colour penetration of yarn. Traditionally done by hand, the yarn is looped over a hook and rinsed in water to open up the fibers, helping the thread to receive the dye. Once the fibers are open, the yarn is dipped into the dye for up to 48 hours. It is then washed and re-dipped. This process is repeated until the thread is fully penetrated, and the desired colour is achieved. Hank dyed denim is known to have a very soft hand feel, with a vibrant colour. Because this process is very time-consuming, and can only be achieved in small batches, hank dyed denim can be very expensive to buy.
Heavyweight Denim Whilst there is no official division of weights within the denim industry, denim that weighs over 14oz (per square yard) is often considered heavyweight, as that is already a marked depature from high street denim that typically weighs 10-12oz. In denim afficionado circles, some consider 14-17oz middle weight, and everything over 18oz as heavyweight.
Hemming The process of folding over an edge of cut fabric and sewing it in place, to prevent it from unraveling. Typically, denim fabric is folded twice before being fixed into place with a chain stitch machine. Some denim is so thick that it needs to be hammered flat before any stitching can take place.
Hemp One of the strongest, fastest-growing, and oldest raw textiles in the world, hemp is documented as being one of the first plants to be spun into a usable fiber around 10,000 years ago. Hemp fabric has a similar hand feel to linen.
Herringbone Herringbone, also called Broken Twill Weave describes a distinctive V-shaped weaving pattern usually found in twill fabric. It is distinguished from a plain chevron by the break at reversal, which makes it resemble a broken zigzag. The pattern is called herringbone because it resembles the skeleton of a herring. An attractive, subtle pattern it is often used in trousers and shirting, for example, the IHSH-239-BLK and IHSH-209-CHA are two recent examples of this in Iron Heart’s catalogue.
Hickory Also called hickory cloth or hickory stripe. Hickory is a durable, low tension fabric of twill construction. It is a heavier version of the seersucker fabric developed during Britain’s colonial period to keep British citizens cool in warmer climates. The heavier hickory, often indigo dyed or navy, and striped, has a long history within workwear. It was adopted by the railroad companies of the Old West for similar reasons to its use in colonial India and Africa. The loose weave allowed engine workers to keep cool while working in the furnace rooms of steam engines, while at the same time being sturdy enough to tolerate the hard working environment. The dark colouring and distinctive stripes helped obscure the inevitable dirt the clothing would collect. Today hickory is an expensive fabric to create due to it’s time consuming low tension weaving process. The ever popular IHSH-91, and assorted Iron Heart work pants utilize the fabric, retaining the traditional indigo/white striping.
Hidden Rivets To help hold the heavyweight tools that were often tucked into back pockets, rivets were introduced into the back pocket construction of jeans in the late 19th century. From 1937 onwards, they were covered to prevent damaging furniture, saddles, and car seats, the so-called hidden rivet was invented. Hidden rivets are similar to the exposed rivets on the front of a pair of jeans, but they are attached before the stitching is done, rather than on top of the pocket after stitching. This means that the rivet is only visible inside the jeans. Hidden rivets were generally dropped in the 1980s as they are complicated and expensive to attach, but have since featured on premium jeans, produced with an eye on older traditions. For denim afficionados this is especially exciting as eventually the rivet will rub through the denim as a result of long, hard, wear. Iron Heart jeans use hidden rivets at the top of their back pockets.
Hige A Japanese term for 'beard' and 'whiskers', referring to the horizontal fade lines that occur around the lap and crotch section of dyed denim jeans.
Hip-Huggers Popular in the mid-1960s and early 1970s, hip-hugger jeans fit tightly around the thighs, knees, and hips, and have a notoriously low rise with legs that flare from the knee down.
Honeycombs The area at the back of the knee that scrunches up during wear and fades over time. The faded pattern that occurs has been noted to resemble the honeycomb shapes created by honey bees.
Inch A unit of length in the British and American imperial unit system used to measure the waist and inseam of jeans. If a pair of jeans is listed as 32", this means the waist is 32 inches in circumference. 1 inch (or 1") equates to 2.54cm.
Indigo The colour indigo is named after the indigo dye that is derived from the plant Indigofera Tinctoria. Indigo is a deep and rich blue colour that is recorded on the visible spectrum as well as one of the seven colours of the rainbow. The species of Indigofera was originally cultivated in East Asia, Egypt, India, and Peru. The earliest evidence for the use of natural indigo dye is from Peru, dating to around 4000 BC. Indigo dye has been used for dying the cotton used in denim since its inception.
Indigo Dye Natural indigo dye is produced by bunching and tieing Indigofera leaves and placing them into a brick-lined vat filled with fresh water. When the leaves begin to soak, they release glucose and are left steep in the vat for around 10 to 15 hours until fermentation ends. Once the liquid turns a yellow colour it is run into beaters and is treated with wooden oars or machinery. During this time, the yellow liquid turns to a green mass, which turns blue, and then indigo. The final indigo mass is extracted and boiled, filtered, and pressed. The pressed mass becomes dry and is cut into cubes, which is eventually ground down into fine powder ready for use for dyeing fabric. This practice was commonplace until synthetic indigo dye that imitates the Indigofera's dye was produced by German chemist, Adolf von Baeyer in 1878.
Indigofera See 'Indigo'.
Inseam The length measured in the inside of the pant leg, from the crotch seam to the bottom of the inside leg. An inseam measurement should end at the ankle. The waist and inseam measurements work together to determine a pant's size.
Iro-Ochi A Japanese term meaning 'colour-slips'. In regards to denim, iro-ochi refers to the areas of the garment that have faded due to age and wear.
Jacron The patch found on the back of jeans, usually made from real or imitation leather, or paper, and sewn into the garment above the back right pocket. The jacron was first introduced by Levi Strauss & Co as a tool to prevent customers from purchasing imitation jeans. The jacron usually displays company branding, imagery, product-specific information, and sizing details.
Japanese Denim Denim that has been made in Japan. Japan is considered to produce some of the best denim in the world, due to the traditional methods they use to create it. Since the early 1970s, Japanese textile companies started weaving selvedge denim using the same vintage shuttle looms that the Americans were using during the golden era of USA made denim. After World War II, the demand for denim increased, and American mills were forced into mass-production, moving from time-consuming selvedge shuttle looms (which place around 150 weft yarns per minute) to much faster projectile looms (which place around 1000+ weft yarns per minute). Since Japan is one of only a few countries who have mastered the art of producing high-quality selvedge denim on vintage shuttle looms, their denim products are coveted around the world.
Jeans A name for durable work pants that have been made out of denim fabric. Although there are many theories around the origin of the name 'jeans', many have attributed it to Italian sailors from the city of Genoa, where they would bring back stockpiles of fabric from Nîmes in France (see 'Denim'). However, it wasn't until the 1950s that riveted denim work pants started to receive their nickname from American manufacturers.
Jelt Denim Jelt denim is an 11.5oz denim exclusive to the Lee (jeans) company. Due to its tight construction and the twisted yarn, Jelt has been famed to carry the quality of a 13oz denim. The "J" in Lee's 101J jacket stands for "Jelt"
L-2B The L-2B was initially introduced to The US Air Force in the early 1950s. It was designed for use in medium/high-temperature environments. It proved so successful and popular that other branches of the armed forces adopted it too.
Label A fabric tab that is used to identify a brand and product information, usually sewn into the specific garment.
Leather Label See 'Jacron'.
Leather Patch See 'Jacron'.
Left Hand Twill (LHT) In a left hand twill or “S” twist, the wale goes from top left to bottom right on the face of the fabric.  In a left hand twill, the warp gets tightened during the weaving process, thus the result is typically a smoother face to the fabric.  Also as more of the weft (or filling yarn) is seen on the face of the fabric, the denim will often appear to be of a lighter hue than an equivalent right hand twill.
Lefty Left Hand Twill (LHT) - In a left hand twill or “S” twist, the wale goes from top left to bottom right on the face of the fabric, essentially the mirror image of the more common Right Hand Twill weave.  In a left hand twill, the warp gets tightened during the weaving process, thus the result is typically a smoother face to the fabric.  Also as more of the weft (or filling yarn) is seen on the face of the fabric, the denim will often appear to be of a lighter hue than an equivalent right hand twill.

Haraki-san has experimented with a number of LHT denims through the years. The most interesting is perhaps the 19oz LHT used on the “Lefty Trucker” IH-526L (see Lefty). The denim is dipped in indigo, many times over to achieve an atypical, very dark LHT where the weft is no longer white. The result is jeans with an original, hand and han the potential for seriously high contrast fading as both the indigo in the warp, and the weft is knocked out, leaving a great deal of white. More recently, a 21oz LHT has been developed and used in the IH-666-21L and IH-634-21L. A more tradtional LHT, it’s combination with the weaving methods involved in making the flagship 21oz fabric has created a beautiful and unique fabric.
Leg opening The opening at the bottom of each trouser legs. The width of leg openings can vary from manufacturer and cut.
Leg Twist Jeans that are constructed from either right hand twill or left hand twill denim have been known to experience a phenomenon called 'leg twist'. This is where the legs of the jeans twist in the direction of the weave, turning the leg seams with them. One way of preventing this issue is by using a 'broken twill' weave, where the twill line direction changes at every two warp ends, canceling out the leg twisting effect.
Lined Rear Pockets Concealed internal twill cloth lining that increases the longevity of rear pockets
Loom A machine used to make fabric cloth by interweaving verticle (warp) threads and horizontal (weft) threads together. 
Loomstate Loomstate - Loomstate refers to the woven fabric that comes off the loom and has had no post weave processing, such as singeing, anti-skewing, or sanforizing performed to it. Any denim produced before 1920 will have been loomstate. It's about as pure as it can get. So if you like raw denim, loomstate is for you.

At Iron Heart we equate “loomstate” with “raw”, as we see loomstate denim as being the only true raw denim. While the original Iron Heart loomstate denim, the UHR, is no longer in production, it is rumoured that Haraki-san is working on a new one. We await more details with bated breath.
Loop Dyeing Loop dyeing is the process of pulling yarn ropes through indigo vats. Once submerged, they are then laid out to oxidize (often on a factory roof) before returning to the dye bath. This technique is known to create a more consistent shade of indigo than other methods, and requires less factory space to achieve. Loop dyeing is the original process used for dyeing denim.
Loopwheel In the 1920’s through to the 1960’s loopwheel fabric was relatively common, but the complexity and almost glacial slowness of production caused the industry to almost disappear and for most of the machines to be scrapped. The loopwheeler machines are actually circular knitting machines that knit “tubes” of fabric, the only tension used in the knitting process is gravity, the end result being a knitted fabric with virtually no inbuilt stress or tension. A loopwheel machine rotates at just 24 revolutions per minute, a modern knitting machine in excess of 10 times that.  Each machine is only able to knit enough fabric for about 8 -10 shirts per day and can only knit a tube of a fixed diameter, so each size finished Tee or Sweatshirt is actually woven on a different sized machine. Apart from the knitted fabric feeling incredibly soft, it also allows shirts or sweats in the smaller sizes to be made with no side seams, because the largest loopwheel machines are actually quite small, larger loopwheel garments have to be made from cut tubes, thus requiring a side seam construction.  Sweats and tee’s made out of loopwheel fabric are necessarily expensive, but look better and last longer than anything else. At Iron Heart we are proud to use this process on many products in our Cut & Sewn range, including t-shirts, sweaters and hoodies.
Loopwheeled See 'Loopwheel'.
Mercerised/Mercerized Mercerisation is a textile finishing treatment for cellulose fabric and yarn, mainly cotton and flax. It was invented in 1844 by Englishman John Mercer. The process improves dye uptake and tear strength, reduces fabric shrinkage, and imparts a silk-like luster. The chino cloth utilized in the IH-717 and IH-720 is mercerized, the result being a smarter, more attractive pant, that will still stand up to a beating.
Moifit Moifit® is an elasticated technical cloth that is highly breathable and completely waterproof, and is often bonded to the reverse of a garment's fabric. Because of its superior flexibility, it will not alter the maneuverability of the clothing it is bound to.
Moleskin Moleskin is a heavy cotton fabric, woven and then sheared to create a short, soft pile on one side. Clothing made from moleskin is noted for its softness and durability and is extremely windproof for its weight. Its name is derived from the soft brushed hand of the fabric, similar to the skin of a mole. In 2019 Iron Heart started producing a range of very popular moleskin shirts and CPO’s, introducing a future classic to the line up.
Moonstar Moonstar is one of the few factories in Japan that make shoes 100% start to finish in-house. MoonStar has been producing shoes in Kurume since 1873. Kurume first prospered in the rubber industry manufacturing Jika-Tabi, the iconic Japanese split toes shoes and boots. Iron Heart's first sneakers (IHSN-01) were designed by Haraki-san and produced by Moonstar using our flagship 21oz indigo and SuperBlack denim.
Moustaches See 'Hige' or 'Whiskers'.
N1 Deck Jacket You’d be forgiven for forgetting that the N-1 came into service for the US Navy back in the early 1940s, as it has been reproduced and appropriated into men’s fashion for decades. Style icons through the last 40 years such as Paul Newman and James Dean have cemented the N-1 as a classic piece of Americana coveted by anyone who appreciates high quality clothing that is built to last. The evolution of the N-1 is one of function. It started life as a copy of the Army’s “tanker jacket” but it was soon realised that it would need to be changed for working onboard ships. So the storm cuff was moved into the sleeve to avoid snagging, as were the patch pockets. The original colour of the outer shell was navy, but later changed to khaki to increase camouflage on ship and shore, while the alpaca kept the sailors warm during in operations in the harsh conditions of the North Atlantic. All this led to the N-1 becoming the longest-serving military jacket in US history; being decommissioned in the late 1960s hasn’t dampened its popularity with servicemen and civilians alike. Haraki has created a beautifully crafted nod to the N-1 deck jacket that stays true to the form and function of the original because if it ain’t broke, don’t fix it.
Natural Indigo In Japan, indigo became especially important in the Edo period when it was forbidden to use silk, so the Japanese began to import and plant cotton. It was difficult to dye the cotton fiber except with indigo. Even today, indigo is very much appreciated as a color for the summer Kimono Yukata, as this traditional clothing recalls Nature and the blue sea. A variety of plants have provided indigo throughout history, but most natural indigo was obtained from those in the genus Indigofera, which are native to the tropics. The primary commercial indigo species in Asia was true indigo (Indigofera tinctoria, also known as Indigofera sumatrana). A common alternative used in the relatively colder subtropical locations such as Japan's Ryukyu Islands. See also 'Indigo Dye'.
One-washed One-washing is a method used to remove most of the shrinkage out of a fabric.
Open End Denim Open end denim is the most common type of denim fabric used in the market today, woven with cotton yarn that has been processed by using the 'open end' spinning technique. This technique mimics 'ring spun' cotton (see 'Ring Spun Denim') by simulating twists and pressing them into the yarn. It is much cheaper and faster to produce then labor-intensive ring spun denim and is therefore favoured amongst large denim manufacturers. 
Organic Cotton Organic cotton is cotton derived from non genetically modified plants, that is to be grown without the use of any synthetic agricultural chemicals such as fertilizers or pesticides. Its production also promotes and enhances biodiversity and biological cycles. In the United States, cotton plantations must also meet the requirements enforced by the National Organic Program (NOP), from the USDA, in order to be considered organic. This institution determines the allowed practices for pest control, growing, fertilizing, and handling of organic crops.
Ounce See 'OZ'.
Overalls An obvious term for a garment that covers both the upper and lower parts of the body often used as protective clothing when working manually — originally designed as a workwear item made from denim or canvas and a predecessor to the 5-pocket jean. Many designs of overall are still used for their original purpose today, by everyone from mechanics to gardeners, but as with the jean, overalls have found their way into popular culture and fashion too. Iron Heart makes overalls from a number of their hard-wearing, hard-working fabric for you to use as you please.  
Overdye/Overdyed Overdyeing is a process where the fabric is dyed a second time, normally by the garment dyeing method. It is most often used on denim or chambray to add an overtone of color to the indigo. Iron Heart typically overdyes with a black sulphur dye. Over time the black dye will fade away, revealing more of the underlying indigo, which in turn fades as indigo does. The effect is a matte black fabric with a hint of indigo that possesses the potential for fascinating, and quite beautiful, three dimensional fades. All our major jean models and a number of signature jackets and shirts receive this treatment and perennially popular with our customers.
Oxidation In reference to a part of the indigo dyeing process. Oxidation occurs when yarn that has been into an indigo vat is taken out and exposed to oxygen. During the period of oxidation, the indigo-dyed turns blue and permanently fixes to the yarn fiber.
OZ An abbreviation for 'ounce', a unit of weight derived from the British and American imperial unit system. One ounce equates to approximately 28 grams. The weight of denim is calculated in ounces and determined by its heaviness across one square yard of fabric, meaning that a yard of 21oz denim weighs 21 ounces. 
Paisley Paisley or Paisley pattern is a term in English for a design using the buta or boteh, a droplet-shaped vegetable motif of Persian origin.
Patchwork The term used for a customised repair job using fabric patches
Patent No. 139121 US139121A is the patent number that granted Jacob W. Davis and Levis Strauss & Co exclusive rights and usage of their copper rivet design, invented to strengthen the stress points on denim work pants. See 'Rivet'.   
Piece-Dyed See 'Garment Dyed'.
Pigment Dye In it's truest sense, pigment dye is not really a dye at all. Instead, the pigment is fixed onto the fabric's surface with the help of a binding agent. As pigment dye washes off fabric quite quickly, many manufacturers use it to recreate a worn-in look on their garments.
Pimp See 'Pimping'.
Pimping Pimping, as in upgrading or customization, is a service offered by Iron Heart International. By utilizing custom made machinery and tools, Iron Heart International can create a personalized shirt featuring snaps in different colours and metals, from subtle brass rings, through coloured acrylic and nickel Permex, and all the way up to silver snap caps created in Los Angeles by GOOD ART HLYWD. In addition we offer a range of silver sewn-on buttons in different sizes, also made exclusively by Good Art Hollywood.
Piqué Piqué, or marcella, refers to a weaving style, normally used with cotton yarn, which is characterized by raised parallel cords or fine ribbing. Piques may be constructed in various patterns such as cord, waffle, honeycomb, and birdseye piques. These fabrics require the addition of extra yarns, called stuffer yarns. These stuffer yarns are incorporated into the back of the fabric to give texture and added depth to the fabric design. The result is a luxurious, textured fabric suitable for use in a range of garments. Iron Heart have used piqué weaves for a number of summer season designs, from polo shirts to type III jackets.
Placket In modern usage, the term placket often refers to the double layers of fabric that hold the buttons and buttonholes in a shirt. Plackets can also be found at the neckline of a shirt, the cuff of a sleeve, or at the waist of a skirt or pair of trousers. Plackets are almost always made of more than one layer of fabric, and often have interfacing in between the fabric layers. This is done to give support and strength to the placket fabric because the placket and the fasteners on it are often subjected to stress when the garment is worn. The two sides of the placket often overlap. This is done to protect the wearer from fasteners rubbing against their skin, and to hide underlying clothing or undergarments.
Plain Weave On a loom, the warps run the length of the fabric and the weft (or “filling yarn” or just “filler”) run across the width of the fabric at 90° to the warps. On a plain weave fabric, each weft thread crosses the warp threads by going over one and then under the next one, and so on. The next weft thread goes under the warp thread that its neighbour went over and vice versa A plain weave fabric, also known as a 1/1 weave, looks the same on both sides. Examples of a plain weave are chambray and canvas (duck).
Pocket Bag Concealed twill cloth bag used for the front pockets of jeans.
Pocket Stitching See 'Arcuate'.
Poly/Cotton Poly/cotton is produced by spinning a sheath of cotton around a core of continuous filament polyester. The result is a thread with the sewing characteristics and traditional look of top quality cotton, yet retaining the many advantages of synthetic threads.
Polycore See 'Poly/Cotton'.
Pre-Shrunk A term for a a garment that has been washed or sanforized to remove most or all of the shrinkage,
Rail Tracks A term describing the visible fades which appears along the length of the jean's outer seam and resemble rail or train tracks.
Ramie Ramie is one of the oldest vegetable fibers and has been used for thousands of years in garment construction. Classified as a cellulose fiber similar to cotton and linen with which it shares some characteristics. It is one of the strongest natural fibers often used in a blend with cotton to improve durability. Ramie is predominantly known for its ability to hold shape, reduce wrinkling, and add a silky lustre to fabric appearance.
Raw Raw” denim has a high cachet amongst denim aficionados, but what the term actually refers to has been diluted over the past few years to the point where it is often used to describe denim that simply has an even dark blue colour. At Iron Heart we have adopted the purest definition of the term and consider “raw” to be synonymous with “dry” or “loom-state”, that is to say fabric (whether it be denim, or chambray for that matter), that has had no post loom processing performed on it. The best example of this at Iron Heart is the now extinct UHR denim.
Reactive Dyed In a reactive dye a chromophore contains a substituent that is activated and allowed to directly react to the surface of the substrate. Reactive dyes have good fastness properties owing to the bonding that occurs during dyeing. Reactive dyes are most commonly used in the dyeing of cellulose like cotton or flax, but also wool is dyeable with reactive dyes. Iron Heart use reactive dying in many product lines but perhaps most notably in our “Superblack”, non-fading denim, available in heavyweight 21oz for type III’s and jeans, and lighter weights for shirting.
Recycled Denim This term refers to denim made from upcycled or re-used cotton either from pre-used clothing or other cotton goods, or wastage incurred when cutting the individual garmment pieces in the cutting room.
Red Cast Red cast is a term for indigo dyed denim that has a slight reddish tone to it. This occurs in denim that has been dyed with indigo only. Brand new red cast denim will have a slight purple hue to it, and over time and wear, the fabric will fade to a bright and clean blue.
Red Line The coloured line, as seen across many denim selvedge seams, initially served as a way of identifying the manufacturer of the denim (see 'Selvedge ID'). The original red line ID was introduced in 1983 by Cone Mills in North Carolina, the primary supplier of Levis Strauss & Co. In comparison, Amoskeag Mills from New Hampshire used a green line ID. Today, the colour of the line used to identify selvedge denim is mainly decorative.
Red Tab The red tab is synonymous with the Levi's brand, invented by Levi's National Sales Manager Chris Lucier and patented in 1936. The red tab serves as a marketing tool that was conceptualised as a differentiator in reaction to competitor brands mimicking several features of the Levi's jean. The woven red tab started to appear on the right-hand back pocket of Levi's 501 jeans in 1936, and later on to their denim jackets. Over the course of history, the red tab has evolved in very subtle ways, starting with an all-caps "LEVI'S" (See 'Big E'), until the early 70s, where the same word appeared with a lower case "e" ("Levi's"). Today, one in ten pairs of Levi's jeans have a blank red tab that does not include their brand name. To secure the company's exclusive legal right to market clothes with the tab trademark, Levi's must produce a certain percentage of products with a plain red tab.
Right Hand Twill (RHT) Right hand twill or “Z” twist is the most common weave found in denim jeans. In a right-hand twill (RHT) the diagonal twill line or wale goes from upper right to the lower left on the face of the fabric. Because the direction of the weave loosens up fibers in the warp yarn, you typically get a rougher, darker face to the twill and little weft of filling yarn showing through on the face of the twill. Thus, all other things being equal, a right-hand twill denim will appear darker.

At Iron Heart, our RHT jeans range from the classic 21oz flagship denim to the 25oz (XHS) and 14oz denims, at each end of the weight spectrum. All IH RHT denims are designed from first principles and are represent a unique approach the weave.
Rigid Denim See 'Dry Denim'.
Ring Ring Denim Ring ring denim refers to denim fabric that uses ring spun cotton yarn for both the warp and the weft. It is also the most expensive denim cloth to produce. See 'Ring Spun Denim'.
Ring Spun Denim Ring spun denim refers to the traditional method used in preparing cotton yarn for denim cloth production, widely used up until the late 1970s, where it was largely superseded by the modern process of 'open end spinning'. Ring spun cotton is spun using a ring spinning machine that rapidly spins the yarn around a ring mechanism and onto a large bobbin thread, constantly rolling, thinning, and twisting the fibers in a consistent direction. This technique generates an uneven, harder wearing, smoother, and stiffer denim fabric, compared to 'open end spinning', which is less labor-intensive, cheaper, and faster to produce.
Rinsed If denim is described as "rinsed", it will mean that the garment has been subjected to a basic rinse, rather than a full wash. The rinsing process removes any excess dye, can help to stop the colour from running, and makes the fabric that little bit softer to touch. 
Rise The distance between the top of the waist brand to the middle of the crotch seam. The size of the rise will determine where the waistband will sit on your body, and can be of importance when looking for a particular fit of jeans. The size of a rise can range from low to high (the average rise is around 7" - 12").
Riser See 'Yoke'.
River Washing A mechanical washing technique used to give denim a vintage look with a soft hand feel. Today, river washing is an unpopular choice due to its negative environmental impact, which requires pumice stones and cellulose enzymes. A similar method to stone washing. See 'Stone Washing'.
Rivet The rivet is a metal fastener designed to reinforce and strengthen potential stress point on a pair of pants, particularly the pocket corners. The process of riveting pants was invented by Jacob Davis, a Reno Nevada tailor, who patented the design with Levi's Strauss for exclusive use on their "waist overalls" (now known as "jeans") in 1873. Rivets are often made of copper or a similar metal alloy and are now a distinguishable feature of classic denim jeans.
Rope Dyeing Roped dyeing is the process of twisting denim yarns into a rope and repeatedly dipping them into vats of indigo. Between dips, the indigo-dyed yarn is able to oxidize. The more dips the yarn receives, the deeper and darker the indigo colour becomes. Because the dips are frequent but brief, the dye does not have the chance to fully penetrate the yarn, meaning the core remains untouched. This creates a denim fabric that fades faster than those with fully penetrated indigo yarn (such as 'hank dyed' yarn). Rope dyeing is noted as the best method for indigo dyeing yarn.
Rope Effect A term used to describe fading along the hem on a pair of jeans, so called because it resembles the pattern of a rope.
Roping See 'Rope Effect'.
Run-off Chainstitch is a decorative sewing style in which each stitch is connected to the next so that they form a chain. Chainstitch run-off extends the stitching to past the end of the seam and leaves a chain-like thread hanging from the seam. Some people love these, as it shows that the shirt has undergone chainstitch construction, others hate it and cut them off, which can be done with no harm to the integrity of the seam.
Sanforised/Sanforized Sanforization is a post weave process, patented by Sanford Lockwood Cluett in 1930.  It is a method of shrinking and fixing the woven cloth in both length and width before it is made into garments and other items.

Sanforisation involves feeding moistened fabric into a machine, then applying heat in the form of steam, and compacting  pressure applied by a flexible rubber tube. The effect of this action is a shortening of the warp yarns, which packs the filling yarns (weft), closer together: at this moment, shrinkage occurs. After compaction, the fabric enters a dryer where the fibers are locked in their shrunken state as the moisture is removed from the fabric. Although sanforised denim will stretch with wear, it will always return to its post-sanforization dimensions when washed.

While raw, unsanforized denim is prized by many in the denim community for its perceived authenticity, Haraki-san often prefers a lightly or fully sanforized fabric, for the even, smooth hand and predictable fabric behavior it offers.
Sateen Satin is a weave that typically has a glossy surface and a dull back. The satin weave is characterized by four or more fill or weft yarns floating over a warp yarn or vice versa, four warp yarns floating over a single weft yarn. Floats are missed interfacings, where the warp yarn lies on top of the weft in a warp-faced satin and where the weft yarn lies on top of the warp yarns in weft-faced satins. These floats explain the even sheen, as unlike in other weaves, the light reflecting is not scattered as much by the fibers, which have fewer tucks. Satin is usually a warp-faced weaving technique in which warp yarns are "floated" over weft yarns, although there are also weft-faced satins.  If a fabric is formed with a satin weave using filament fibers such as silk, nylon, or polyester, the corresponding fabric is termed a satin, although some definitions insist that the fabric be made from silk. If the yarns used are short-staple yarns such as cotton, the fabric formed is considered a sateen. A satin fabric tends to have a high lustre due to the high number of floats on the fabric. Because of this, it is used in making bed sheets. Many variations can be made of the basic satin weave, including a granite weave and a check weave. Satin weaves, twill weaves, and plain weaves are the three basic types of weaving by which the majority of woven products are formed.
SBG SBG is an acronym for our popular "Super Black Fades to Grey" denim and was made to provide customers with a truly black denim that will also age with wear in the same way as indigo denim. This denim fabric is woven with a black sulphur rope dyed warp and a black reactive dyed weft. Over time, the rope dyed warp will fade, but the reactive dyed weft will not, creating tones of grey in high-wear areas. The result is jeans with the same potential for the unique, personalized expression that denim afficionados love in their indigo jeans.
Seam Twist See 'Leg Twist'.
Self-Edge See 'Selvedge'.
Selvage See 'Selvedge'.
Selvedge The terms selvage (US English) and selvedge (British English) are a corruption of ‘self-edge', and have been in use since the 16th century. Selvedge/Selvage is the term for the self-finished edges of the fabric. The selvedge keeps the fabric from unraveling or fraying and is a result of how the fabric is created. When it comes to denim, selvedge fabrics are created on a shuttle loom, the action of the shuttle being responsible for the finished edge.

Selvedge fabric is largely considered to be superior to non-selvedge fabrics within the denim community, although this is not longer always the case. The quality of the cotton, the design of the fabric, the type of loom used and the skill of the weaver are the most important factors that affect the quality of the denim. A lack of these factors in the production of selvedge means that fabric with a selvedge ID can be of a mediocre or even poor quality. At the same time, fabric woven on projectile looms, with these factors present can be superior to other selvedge fabrics.

Iron Heart produces a range of selvedge denims, chino and shirting fabrics woven on a variety of often vintage shuttle looms, by weavers with generations of experience, as well as premium quality non-selvedge fabrics.
Selvedge ID Selvedge ID is the term used to describe the often coloured or pinstriped self finishing edge, as seen on the border of selvedge fabric. Some brands choose a thread colour or vary it from cut to cut. Iron Heart use the traditional red line selvedge ID, almost exclusively. Displayin the selvedge ID (subtely, or otherwise) is popular amongst denim afficionados, althought the ID itself is meaningless in the context of the quality of the denim. Selvedge denim that does not display the selvegde ID is still selvedge denim.
Serge Serge is a type of twill fabric made with a two-up, two-down weave. The finished fabric features a flat, even diagonal rib pattern on both the face and reverse that distinctive from the zig-zigging pattern in left or right hand twill denims. The attractive,  even, regular patterning combined with the inherent toughness of a twill fabric, made it suitable for military uniforms. Today Iron Heart uses a range of serges, from their ever present 12oz Wabash serge, to specially woven serges used in shirting.
Serge De Nîmes Nîmes is a French city located in the region of Occitanie, Southern France. Famous for its textiles, Nîmes is responsible for producing a serge fabric which is now known as "denim". Simply put, "serge de Nîmes" means "serge from Nîmes". And because the "s" is not pronounced in french, the name was understood as "serge de Nîm" or "serge denim" in english. Over the years, this phrase had been shortened to denim.   
Shell Cordovan Shell cordovan (or cordovan) is a type of leather commonly used in high-end shoemaking. Cordovan is an equine leather made from the fibrous flat muscle beneath the hide on the rump of the horse. The leather derives its name from the city of Cordoba, Spain, where it was first practiced by the Visigoths in the seventh century, and later also by the Moors. It is called "shell" because the shape of the tanned leather resembles an open shell. It is a difficult and expensive leather to make, and in the late 19th and early 20th century was mostly used for razor strops to sharpen razors in barbershops.

Despite it’s cost, shell cordovan has a number of distinctive qualities making it sought after. The leather has a luxurious, smooth and glossy finish, requires very little maintenance, and is remarkably hard wearing. It’s aesthetic and practical qualities make it an excellent choice for heirloom leather pieces such as wallets. The IHG-01 and IHG-02 wallets are excellent examples.
Shrink-To-Fit A term trademarked by Levi Strauss & Co, referencing their raw, unwashed, unsaforized denim that's been taken straight off the loom (see 'Loomstate'). Jeans made from unsanforized denim will shrink anywhere up to 10% in size when washed. Levi's capitalized on this concept and marketed "Shrink-To-Fit" denim, where they encouraged customers to purchase jeans two sizes up, and shrink them for a custom fit. Some methods would include wearing them in the bath and keeping them on while they dried.
Shrinkage Yarns and/or fabrics are not fixed materials. They consist of separate fibers that will stretch when exposed to tension, i.e., they elongate during the process of being made into cloth (during spinning, weaving, bleaching, dyeing, and the various finishing processes, yarns and cloth are under continuous tension).  Some or all of this stretch within the fabric is retained in the post-loom fabric because of friction between the fibers and the yarns. The stretch that occurs can be eliminated when the friction within the fabric is reduced.  This will happen during soaking and/or washing, where both water and soap act as lubricants.  The lubricants, along with the mechanical action of the washer, help the fibers relax and contract (shrink) back to their original length. One of the reasons that dry cleaning does not shrink natural fabrics is that the friction within the fabric is not reduced by dampening.
Singeing In manufacturing, 'singeing' is the act of using a controlled flame to burn off any loose or stray fibers from a newly made denim product.
Skein Dyeing See 'Hank Dyeing'.
Skewing Leg twist in jeans made of twill fabrics may be avoided by skewing the fabric clockwise or counterclockwise depending on the twill direction before making the garment so that when the garment is laundered, the positions of the warp and filling yarns will remain unchanged with respect to each other.
Skinny Fit A skin-tight snug fit jean cut that follows the shape of the leg, all the way to the ankle. The 1960s is considered the golden age of the skinny jean, being a popular cut amongst mods and rock and rollers. Since then, the skinny jean's popularity has barely tapered, with a resurgence in popularity hitting the mainstream from the late 00s to today.
Slim Fit Slim fit jeans are fairly tight around the thighs with a narrow cut that tapers from the knee to the cuff. Looser than skinny fit jeans, and much slimmer than straight cut jeans. At Iron Heart we consider the 555, 666 and 777 to be slim fits, all with varying amounts of taper and rise height.
Slub A slub is a thick piece of yarn or thread that creates an inconsistency on a woven piece of fabric. In denim, this often occurs during the use of vintage shuttle looms, where some areas of the cloth become thicker than others. Initially seen as a flaw, slubs or "slubbyness" are now purposely added to select rolls of denim, as it is considered to add character to garments.
Slubbyness See 'Slub'.
Sprung Sterling Silver "Simply put, sprung silver is silver that has a spring to its structure. You can turn many metals into springs by aligning the molecules in such a way as to make them more prone to holding a particular shape. This is usually done with controlled heating & cooling cycles or by striking the metal repeatedly. Once the metal is sprung, when pushed out of its resting shape, it will then have the tendency to go back to that shape. Pushed beyond the limits, it will fail. The best metals for springing have a high content of iron, like steel. We have techniques to give that spring and bounce to Sterling silver. Spring silver or sprung silver are known terms in jewelry manufacturing, but the techniques are not common, most folks are too lazy to make things requiring it" - Josh Warner, GOOD ART HLYWD
Staple In textiles, staple refers to a unit of length. Cotton has a range of lengths from short to long, and the staple length is the average. In denim making, a longer staple length has a much higher value as it's easier to spin and can create a stronger, softer yarn.
Stone Washing Stonewashing is a washing process designed to fade, age, and soften denim garments. This is achieved by adding the garment into a washing machine filled with pumice stones. During this wash-cycle, the pumice stones bash, roughen up and abrade the fabric. This process has become an unpopular choice due to its negative environmental impact, where the ground-up pumice stones are difficult to recycle or dispose.
Straight Leg A jeans cut where the legs run in a consistent width from the thigh to the hem. Straight leg jeans are considered an original classic cut and have been popular since the release of the Levi's 501 in 1890.
Stretch Denim Stretch denim is a denim fabric that has been woven with a small amount of elastane (see 'Elastane'). Elastane usually makes up for around 2% of the weft fiber, with the rest being cotton. Stretch denim is known to be stretchy, flexible, soft, and comfortable, and is often used for tighter jeans cuts, allowing for improved movement.
Sulphur Bottom An economical way of producing a deeper shade of indigo denim using less indigo dye. Sulphur-bottom is the process of adding sulphur dye to the denim fabric before it is dyed with indigo, reducing the amount of time that is traditionally needed to create deep indigo tones. Although this method has been noted to lessen production time, sulphur dyed fabric has been known to retain a yellow or grey cast.
Superblack Term used for Iron Heart denim that has been woven with a black reactive dyed, or enzyme dyed, warp and weft. The colour of this fabric is deep, dark, and super black that will not fade like indigo or sulphur dyed denim. Currently available in 21oz and 12oz, Iron Heart use their Superblack denim for a range of jeans, jackets, vests and shirts.
Supima Supima is the trademark of the Supima Association, which promotes American Superior Pima cotton. Supima is twice as strong as regular cotton, which makes for extraordinarily resilient products. The longer fiber (around 1.4inches) resists pulling, breaking, and tearing, resulting in a garment that is incredibly resilient, very soft/silky, will retain its colour and keep its form for longer.
Synthetic Indigo First produced by German chemist, Adolf von Baeyer in 1878, synthetic indigo dye imitates the Indigofera plant's natural dye properties. The molecular structure of natural and synthetic indigo is identical. Today, the synthetic version has almost entirely replaced the use of natural indigo dye as it is less time consuming and can be produced on an industrial scale. See 'Natural Indigo'.
Tab The small but recognizable label usually sewn into the right-hand side back pocket of denim jeans. See 'Red Tab'.
Tapered Jeans A jeans cut where the legs become narrower (or taper) down towards the ankle. The range of cuts currently produced by Iron Heart that feature a taper are the 555, 777 annd 888 lines.
Tate-Ochi A Japanese term for the vertical fading lines on worn vintage denim. The literal translation of "tate-ochi" is "vertical falls". This fading normally occurs in denim made from slub yarn (see 'Slub') and is highly prized in Japanese denim communities. Iron Heart’s 25oz and vintage style, 18oz denims have a strong tendency for vertical fading.
Tea Core Tea-Core is a leather with low depth dye penetration, this results in tones of brown appearing in high wear areas.
Triple Needle Stitch A triple needle is a needle with a single shank and three shafts that stitch three parallel seams in a continuous line. Triple stitching is a common technique used for making workwear, to reinforce yokes, hems, pocket fixings, and many other parts of a garment that requires strengthening.
Trucker Jacket The trucker jacket is the name given to a denim jacket that has a pointed collar and two chest pockets with pointed button plackets. Also known as the Type III, this style of jacket was first introduced by Levi Strauss & Co in 1962 and has since become a modern design classic.

While Iron Heart produces a range of classic denim jacket styles, our type III interpretation is by far and away the most popular. Available in many different materials, including assorted denims, corduroys and even horsehide leather, the design of the Iron Heart type III trucker jacket has recently been updated to feature a slightly longer body and cleverly incorporated handwarmer pockets which also double as spacious internal pockets. 
Turpan Turpan, also known as Turfan or Tulufan, is a province of China, famed for the production of Extra Long Staple (ELS) cotton of the highest quality (think, Sea Island Cotton). Fabrics woven from Turpan cotton have a natural sheen to them.
Twill Just like a plain weave, a twill fabric consists of warps and wefts. However, in a twill weave, the weft passes under one or more warps and then over two or more warps. The next weft will “step” or offset one warp, this creates the characteristic diagonal line (known as a “wale”) that identifies a twill fabric. Twill weave is often designated as a fraction such as 3X1, where the weft passes over three warps and then under one (three up, one down). The 3x1 twill is used for any denim that is 10.5oz or over. For denim weighing under 10.5oz, a 2x1 twill weave will be used. Twills have a front and a back side and look different on the face and the back. Because a twill fabric has fewer interlacings than a plain weave, it allows the yarns to move more freely, which is one of the reasons that denim, which is a twill, shapes to the body well. How the weft thread is woven will determine the overall strength and aesthetic of the finished fabric. Finally, because a twill has an uneven surface, stains are less noticeable than on a plain weave fabric, which is good for workwear such as jeans. Although this technique is used in denim making, it is not limited to cotton. Linen, wool, and silk are amongst some other popular choices for the twill weave. 
UHF Dating back to 2009 when it was first used to describe the IHSH-20, UHF is an acronym for Ultra Heavy Flannel. Made from brushed Aspero cotton and highly sought after, Iron Heart’s UHF’s epitomize the brands attitude to clothing. Tactile, comfortable and utilitarian, due to the warm, soft, windproof material. Eye catching and unique thanks to the sharp work shirt and western cuts, and beautiful patterns and colourways Haraki-san devises each season.
UHR UHR is an acronym for "Ultra Heavy Raw", a term used for our now defunct ultra-heavyweight raw Japanese denim. An unsanforised and loomstate fabric, UHR denim fabric starts at 21oz, and becomes (approximately) 23oz after shrinkage. It is a lighter shade of indigo than most other Iron Heart denims. The UHR enjoys virtually legendary status amongst afficiando’s and fans of the brand, due to its fading potential, an the density of the weave.
Union Special Established in 1881, Union Special is the oldest, largest, and the last of the industrial sewing machine manufacturing companies in the United States. In 1939, they produced a chain-stitching machine that is still used within the heritage denim industry today, known as the Union Special 43200G. This machine is famous for its tight and robust chain stitch that creates the world-renowned 'roping effect' when hemming jeans. A result that can't be mimicked by today's modern machinery. Because production of the 43200G ceased in 1989, this machine is highly prized and requires specialist knowledge for maintenance and care. 
Unwashed Denim See ' Dry Denim'.
Vulcanised/Vulcanized Vulcanization is a chemical process whereby the physical properties of natural or synthetic rubber are improved. The finished rubber has higher tensile strength and resistance to swelling and abrasion, and is elastic over a greater range of temperatures. In its simplest form, vulcanization is brought about by heating rubber with sulphur.
Wabash The name ‘wabash’ comes from the Indian Wabash tribe of the American mid-west.  They modified workwear staples that were made of denim and then traded them to the white men who worked in manual labor positions as ‘decorated workwear’. Wabash looks like quite a formal fabric, but in fact, it was commonly used for workwear from the early 1800s through to the early 1900s, very often as uniforms for the massive US railroads workforce. 

Finding out a lot about Wabash is very difficult, but we believe there were 2 ways in which the dots were originally ‘applied’ to the base fabric: 1) the pattern would be applied as a block print to the undyed fabric with a starch based “resist” and then dyed, the dye not adhering to the resistant pattern; and  2) the fabric was dyed and then the pattern bleached into the fabric - this was done by applying a mildly acidic solution to the cloth via copper rollers with the pattern raised from the surface of the roller, a process known as discharge printing. 

Perhaps the most famous of the American Wabash dying and printing companies was J.L. Stifel & sons set up in West Virginia in 1835.  They called their product ‘Indigo Wabash Stripe’, and it was often characterized by an impressive assortment of dots, triangles, and diamonds.  A few examples of these can be found in ‘King of Vintage vol 3’ by Rin Tanaka.

Iron Heart has a great love for Wabash and it has been used in shirting on a number of occasions. Our established Wabash fabrics weigh 12oz and are designed from first principles by Haraki-san and are available in indigo, sulphur dyed black, and white. The indigo and black iterations are created utilizing the discharge printing technique, but first, both the weft and the warp are separately rope dyed then woven to create a serge fabric.  This fabric is then discharge printed to create the dots.  Because we use a rope dying technique for the base fabric, the garments created from it will age with great character. The IHSH-62 and IHSH-68 lines made from this fabric are mainstays of our product line, as are the IH-814 painter pants and IHV-02 work vests. The same process is used to create our hefty 21oz Wabash, recently utilized in the IH-824 and IH-825 jeans and IHV-30 vests.
Waist Overalls The original term used to describe riveted workpant, coined by Levi Strauss & Co in 1873. It wasn't until the 1950s that waist overalls started to be called "jeans".
Wale The ribs, or wales, are what gives corduroy it’s distinct quality, and the number of wales lets you know what kind of cord you’re dealing with. When you see a wale number given, it’s telling you there are that many ribs per inch, so the higher the wale number, the finer the wales will be. Classic corduroy typically has 14 wales per inch.
Warp In weaving, the weft is the term for the thread or yarn which is drawn through the warp yarns to create cloth. Warp is the lengthwise or longitudinal thread in a roll, while the weft is the transverse thread. A single thread of the weft, crossing the warp, is called a pick. Terms do vary (for instance, in North America, the weft is sometimes referred to as the fill or the filling yarn).
Weft In weaving, the weft is the term for the thread or yarn which is drawn through the warp yarns to create cloth. Warp is the lengthwise or longitudinal thread in a roll, while the weft is the transverse thread. A single thread of the weft, crossing the warp, is called a pick. Terms do vary (for instance, in North America, the weft is sometimes referred to as the fill or the filling yarn).
Weight Industry-wide, denim is graded by weight. The weight of denim is determined by its heaviness across one square yard of fabric, meaning that a yard of 14oz denim weighs 14 ounces. There are three weight grades of denim: light, medium, and heavy. Lightweight denim is considered to be under 12oz. Mid-weight is between 12oz-14-oz, and any denim weighing over 14oz is considered to be heavyweight.
Whipcord Whipcord (also known as jungle cloth), is a strong worsted or cotton fabric made of hard-twisted yarns with a diagonal cord or rib. The weave used for whipcord is a steep-angled twill. The ribs of whipcord are usually pronounced and the weft (filling) may be visible between the ribs on the right side. Whipcord is usually found in durable outdoor clothing (typically pants, sometimes jackets), or in durable workers' clothing (typically overalls). The tightness of the weave means the fabric has excellent windproofing qualities and is performs better in wet conditions than most other cotton fabrics.
Whiskers A term that refers to the horizontal fade lines that occur around the lap and crotch section of dyed denim jeans. See also 'Hige'.
Woad Istatis tinctoris, or 'woad', is a yellow-flowered plant from the Brassicaceae family (cabbage, broccoli), and was an essential source of the natural blue dye commonly used in textiles before the introduction of indigo from Asia. Native to southern Russia, woad was cultivated throughout Europe, with woad-growing regions in Germany, France, and England during the medieval period. As a natural colour dye option, woad is still used today, although indigo is highly favoured due to its much better colourfastness.
Workwear Traditionally, workwear is heavy-duty clothing often worn for physical or manual work. Designed to be durable and practical, the workwear 'style' has gained popularity outside of its function.
Worn-In Denim "Worn-in", or "worn-out" denim, is denim that looks aged and faded, achieved over time through wear by the user. Although, some brands have been known to artificially 'wear-in' their denim products through various "finishing" methods, such as stone washing, hand sanding, and even lasering. 
XHS XHS is an acronym for "Extra Heavy Selvedge", a term used for our ultra-heavyweight Japanese selvedge denim. Weighing in at a mighty 25oz, there may be heavier denims out there, but Haraki-san believes that 25oz is at the upper end of what is can be comfortable and practical, and who are we to argue with him. A deep, dark indigo colour when new, the denim has an almost legendary reputation thanks to its unique qualities. While it is understandably stiff and challenging to use at first, it slowly softens with wear and tear to remarkable levels of comfort, while at the same time developing high contrast fading with a special tendency towards “tate-ochi”, or vertical fading.
XX The original model number used by Levi Strauss & Co for all 501 jeans produced before 1890. "XX" stood for "Extra Extra Strong" and had been present on the 501 jacron until 1968.
Yarn A long and continuous length of interlocked fibers used for weaving fabric.
Yarn Dyed Yarn dyed refers to fabric that is woven with pre-dyed yarn. This is a standard method in denim production, where the warp yarn is indigo dyed before being woven into denim fabric.
Yoke A yoke is a shaped pattern piece that forms part of a garment. The yoke on a pair of jeans is v-shaped and can vary in size to create the desired shape and curve of the seat. On a shirt, the yoke usually fits around the shoulders and neck, and can often be made from a double-layered fabric to withstand the weight and friction of jackets and bag straps.
Z-Twist See 'Right Hand Twill (RHT)'.
Zipper Fly Invented by Whitcomb Judson in 1851, the "zip" is a mechanical device used to fasten two edges of fabric by passing a slider over two rows of interlocking metal teeth. The Lee (jeans) company claim to be the first brand to use a zipper fly for their 101Z model jeans, released in 1923. It wasn't until 1954 that Levis Strauss & Co followed suit, releasing a zipper fly version of the 501, known as the 501Z. While most of Iron Heart´s jeans utilize a button fly, cuts with we continue Levi's traditions by including a "Z" in the lot number of all iterations which incoporate a zipper fly. for example the IH-634Z. A zipper fly is also used on our chino's and work pants.
  • Register

Register Account

Already have an account?
Log In Or Reset password