There are a ton of terms and processes used within the washing process to give denim different fades, looks, textures, etc. Here, we break down the most commonly used washing terms and techniques.

abrasion The designer tries to make garments look worn or faded by scraping or rubbing the surface of the fabric causing abrasion. Pumice stones, sandpaper, grinders, etc provide mechanical abrasion. Enzymes, bleach, permanganate and reducers are used to get chemical abrasion.

acid wash Most popular in the 80s. The process is achieved by soaking pumice stones in chlorine bleach and then dry tumbling them with jeans before washing. This creates very irregular, hi contrast splotches over the entire surface of the garment.

bleach Bleach is used to make jeans fade. Liquid bleach is usually an aqueous solution of sodium hypochlorite, and dry powdered bleaches contain chloride of lime (calcium hypochlorite). Chlorine bleach attacks all colors in fabric both indigo and sulfur so it needs to be used sparingly as it flattens the look of the fabric. Good laundries will use longer wash cycles and less bleach to achieve maximum hi/low effects.

balloon form (or mannequin) Mechanical form made of heavy-duty inflatable rubber that mimics shape of human legs. Garments are put on the form when machine sanded or PP sprayed to control garment stability and give more natural blast patterns. Balloon forms can come in adult or children's sizes, also they can come in jacket forms.

contrast Very useful term when describing the desired blast effect. In describing blasts, you should avoid terms like "lighter" and "heavier" as they can be misleading. (For instance you may say you want a lighter blast, meaning you want it to be lighter in color, but laundry may mistake this for lighter intensity and will give you a darker, less apparent blast.

In general:
Hi-contrast means you want the blast area to be very apparent, and stand out against the ground color (base wash) dramatically. Using PP (potassium permanganate) will give you hi-contrast effect.

Medium-contrast is most common - you get a nice contrast between blasted area and ground, not too dramatic, but not soft enough that it is invisible. Usually achieved by sandblasting or machine brushing.

Low-contrast means you want blast to be subtle, and very soft, with minimal color loss. Generally hand sanding gives you the softest blast effects, but hand sanding will disappear in lighter washes.

chevrons The lines that form on inner thighs of jeans (as opposed to lap which are called whiskers) from continued wear. The process is the same as used to apply whiskers - by hand using either a sanding tool alone or with PP depending on contrast desired.)

de-sizing The wet processing operation of removing the warp size chemicals and finishing starch from the fabric. Laundries generally use amylase, a starch-busting enzyme found in saliva, or alkaline chemicals like soda ash to remove the sizing. If sizing isn't removed prior to washing streaks and cracks can result. For darker washes a fixing agent is added during de-sizing to hold dye in the fabric and decrease crocking. (also see sizing in fabric terms)

enzymes Cellulose enzymes (a protein-like substance) are used to actually eat away at the cotton fibers and create a stonewashed look. The combination of the surface-to-surface abrasion of the garments and the garment to machine abrasion creates an overall stonewashed appearance.

feathering The term used when you want to explain to the laundry that you want a nicely blended blast pattern. A typical blast should look strongest at the center, but gradually decrease in intensity at edges so that it blends into the ground color, with no harsh lines. To get feathering the laundry may need to hand sand around sandblasted area to soften the lines. (see sandblasting and contrast).

flat Calling a wash flat can be either good or bad depending on what look you ware trying to achieve. When used as a negative, it means you do not see enough contrast between blue (ground) and white (fill yarn or fabric slub). This can occur from washing with only enzymes without stones, or from poor cleaning up of the garment in the wash. (see re-dep) When used as a positive, it means you want the denim to wash down very cleanly and evenly, and only want hi/lows on seams not on surface (see flat finish in fabric terms).

grinding and nicks Using a mechanical device to chip away at the fabric to break the yarns and get small tears. The difference between grinding and nicks is amount of surface covered. Grinding is generally any tearing of � inch or more in length while a nick is any tear under 1/4 inch in length. Most commonly used at bottom hem and pocket edges, but you can specify grinding or nicks on any part of the garment.

hand sanding Using sandpaper to scrape away the top layer of indigo from the fabric. Hand sanding denim gives it the most natural, worn effect as the laundry operator can adjust the pressure used, and blend the blast pattern with the ground.

laundry A manufacturing company that takes unwashed jeans, and processes them. This processing includes washing, stone washing, sandblasting, and garment dyeing. Laundries today are critical in making jeans look commercial and wash development has become equally important to fabric development in the denim industry. The best laundries and wash developments come from Italy, Japan and the United States.

machine brush A high powered electrical steel bristle brush that when run over denim quickly chips the indigo away. Sandblasting and machine brushing give very similar effect.

pocket outline A surface technique where the jean is placed on the balloon form, and the laundry technician heavily hand sands over the pockets. The pressure of the sanding accentuates the inside seam of the pocket bag and you see it on the jeans surface. This gives a more natural effect than drawing the shape onto the garment.

potassium permanganate (PP) A dark purple crystalline compound, KMnO4, used as an oxidizing agent and disinfectant and in deodorizers and dyes. PP can give very dramatic hi-contrast blast patterns. PP when applied is a purplish color but garments are then neutralized which causes the areas where PP is applied to turn white. PP can be applied by spray to get overall blast pattern, or can be applied by brush or sponge to just affect specific areas

pumice stones Pumice stones are used in wash to chip away layers of indigo from the denim. Pumice is volcanic and is used because of its strength and lightweight. The preferred pumice to use is Turkish White Pumice Stone as it has the best porosity and cleanliness. Turkish white pumice should be specified when doing light washes or stonewashing twills as it leaves less residue on fabric.

re-dep (short for re-deposition, also referred to as back-staining) When indigo comes off in wash, but due to poor cleaning the indigo falls back onto the fabric and you get a very flat wash (no hi / lows). The easiest way to tell if the flat look of wash is caused by re-dep is too check the pocket bags, if they are tinted blue then the laundry is not cleaning up after wash, and probably needs to use an anti-back staining agent

reducers Chemicals that remove color from fabric. Special reducers can attack specific dyestuffs like indigo but leave sulfur dyes in fabric to achieve different casts.

resin A synthetic polymer that is used to set wrinkles into a jean. Jeans are treated with resin, and then baked in an oven so chemicals can merge with fibers to set color, stiffness, and make creases permanent. Resin will set color into the jean, so will reduce crocking where applied. But be careful, as resin will effect the denims tear/tensile strength and make the fabric weaker and more brittle. Also resin contains formaldehyde so may be problematic for production of children's jeans.

rigid denim Unwashed denim. Some mills use this term to refer to non-stretch denim, though to avoid confusion with garment makers it should be reserved as a wash term and use the terms stretch and non-stretch for fabric type.

rinse The mildest, least severe garment wet processing finish during which the sizing, natural waxes, pectins and starches are removed from fabric. Only a minimal color loss is achieved.

sand blasting A laundry process where jeans before washing are literally shot with a high-powered spray of sand that chips off the outer layer of indigo. While actual sand was originally used now most laundries use very small aluminum oxide pellets. If blast is applied improperly you can get a very harsh, unnatural contrast between the ground and blasted area in the garment.

softeners

Softeners can be classified into the four major groups:

Anionic softeners have poorer affinity for cotton. Most of them show good stability towards heat and have better resistance to yellowing. However, softness of anionic softeners is inferior as compared to cationic, even with high concentration. Also, they are easily removed and have low durability to launderings.

Cationic softeners provide very soft hands at even low levels. They have efficient exhaustion from high or low liquor ratio baths. However, Cationic softeners have a tendency to yellow the garments.

Nonionic softeners have little effects on fabric shades and are quite non- yellowing. However, the hand is not as good as the other softeners. It is not as durable as cationic, but more durable than anionic softeners.

Silicones impart a silky, slick, greasy, full hand on the surface of the materials. It improves the abrasion resistance but reduce absorbency. Normally, silicones are used with cationic softeners to provide ultra-soft and smooth hand feel.

 
stonewash The most common way to wash denim. Pumice stones, in combination with enzymes (and sometimes bleach), are added in the wash to get abrasion on denim. Water temperature, stone size and length of load time all affect final wash appearance.

tacking A technique that folds or scrunches several layers of denim, and attaches it together by swift tach or sewing thread before wash. After wash it is released to reveal a pattern of light areas where stones hit the folds, against dark areas where wash did not penetrate.

tinting (also called over-dyeing) Laundries often tint denim to try to make it look more vintage, or to achieve a different cast. The telltale signs of a pair of jeans that have been tinted are that the pocket lining and labels are dyed as well as the jeans.

whiskers The lines that form on the lap and legs of jeans from continued wear. Most whiskers are applied at the laundry by hand using either a sanding tool or PP depending on contrast desired.