Hello, and welcome to the Steel Feather Denim Glossary! The terms and expressions used by denim experts and aficionados are plentiful. Explained here are some I often use myself:

Ai – the Japanese expression for natural indigo. Hence the “AI” of the Steel Feather SF02AI jeans. Not to be confused with artificial intelligence (AI). Natural indigo dyestuff is extracted from plants, through a time consuming process, which is why it’s usually quite expensive. Ever since the invention of synthetic indigo, natural indigo is much less used; however, natural indigo is still found in more exclusive denims. See also, synthetic indigo.

Atari – a Japanese term for the various fades and aging of a pair of jeans. Not to be confused with the gaming system of old.

Chainstitch – a widely used stitch in the construction of jeans. This stitch can be done with a range of machines, however they are usually specialized for the different steps of the jeans construction. The sought-after Union Special 43200G series sewing machine specializes in the hemming of jeans, and it produces this type of stitch.

Cuffing – the exquisite art of folding up your hem to make your jeans shorter, or to show off that selvedge. The results are highly connected with individual tastes.

Darning – the process of darning is a means of “reweaving” (or replacing) fabric into ruined and worn-out parts of a garment. This is a superior method of fixing holes in your jeans, rather than patching. However, some people may prefer the aesthetics of patched jeans.

Denim mill – a factory that weaves denim fabrics, such as Nihon Menpu, Kuroki, etc.

Kibata – a Japanese expression that translates into loomstate, meaning straight off the loom. Kibata denim is untreated and raw denim straight off the shuttle loom. Kibata will have many traits the denim aficionados appreciate, such as being unsanforized and unsinged. The former refers to the pre-shrinking of the denim, and the latter refers to the singing/burning of excess fibres on the outer surface of the denim. Unsinged denim is characteristically “hairier” than its singed counterparts.

Natural indigoSee Ai.

Oz. – a denim is often distinguished by its weight in Oz. The higher the Oz. value the thicker and heavier the denim. I was once asked why unsanforized/shrink-to-fit jeans increased in Oz. weight after washing, and this is because the Oz. is calculated per square yard. When the fabric shrinks and tightens together, the density within the square increases. However, the total weight of your jeans remains the same.

Pre-distressing – a collection of techniques and processes intended to replicate a worn effect on jeans. The results are of extremely varying quality. Generally, real denim aficionados do not appreciate this, and (truthfully) neither does the environment.

Raw – refers to denim that is unwashed and otherwise chemically untreated. Also known as dry denim. Pre-distressed denim is not considered raw.

Rivet and burr – the small and round metal fasteners that are found in the stress-points of the jeans. The rivet is the “spikey” part and the burr is the (usually) round disc that the rivet is punched through. This famous detail for increasing the durability of jeans was famously invented by Jacob Davis.

Rope dyeing – a technique used to dye yarn (commonly, the warp yarn), which leaves the core of the yarn lighter. The yarn is wrung after each dip in the dye bath, squeezing out excess dye. More dips result in a deeper color. During this process, the twisted yarns will look like rope. Denim woven with warp yarns dyed in this manner will have an enhanced ability to develop strongly contrasting fades. This is due to the white/lighter core of the yarn, and the nature of indigo dyes being non-colourfast.

Sanforization – the process of pre-shrinking moistened denim between a rubber sleeve and a rotating heated cylinder. Sanforized fabrics will shrink minimally with washing. In comparison to unsanforized fabrics, the sanforization does deplete the cotton fibres’ ability to retain shape over time. In other words, it “kills” the cotton fibre; and jeans made with sanforized denim fabric will not fully retain its ability to keep its shape after washes. The process was patented by Sanford Lockwood Cluett in 1930.

Selvedge – the natural edge of a fabric. In Japanese: mimi, which translates into “ear”. This edge is produced by weft thread looping back at each row of warp thread. Also known as selvage (US), and both are a corruption of the term “self-edge”.

Shuttle loom – the industrial narrow looms famous for creating rolls of fabric with their selvedge intact. Steel Feather denim is woven on such shuttle looms, of Toyoda (now Toyota) make. Most of these Japanese looms were not intended for denim weaving, however they were converted and engineered by their owners to produce denim.

Slubbiness – the texture of a fabric woven with varying thread weights in the warp and/or weft. Often referred to as a natural weave. ”This denim has a slubby texture and feel.”

Synthetic indigo – this refers to indigo dyestuff made by chemical synthesis. Synthetic indigo has largely replaced the use of natural indigo in textile dyeing. See Ai.

Unsanforized/Shrink-to-fitunsanforized fabric will shrink with its initial washes, but only up to a certain amount. The amount of shrinkage varies with a great many factors, such as tightness of the weave, how warm you wash them, the Oz. weight of the fabric, the construction and relative size of the garment, etc. The most of the shrinkage will occur along the grain of the fabric (warp), and less cross-grain (weft). This means you should allow for 1-2 inches/2,5-5 centimeters extra in the waist, to get the desired fit after washing. The shrunk unsanforized fabric has the ability to mould to your movement and shape better than a sanforized fabric will, and it retains its shape better because the fibres pull together a little when washed. With each wash (between uses) it reshapes and moulds to your body faster.

Warp and weft – warp is the longitudinal threads that run the entire length of the fabric. A typical roll of selvedge denim is about 50 meters long. Weft is the transverse thread that is shot back and forth with a shuttle (hence shuttle loom) between the warp threads.

Zomé – this is a term related to dyeing, usually by hand, as in aizomé, which means hand dyeing with natural indigo, and as in kase zomé, which is an automated form of dyeing that’s supposed to mimic the effect of hand dyeing. Also see, Rope dyeing, alternatively known as rope zomé.