Denim comes in many finishes, which are known as washes. The term "wash" literally refers to how unfinished denim, which is called dry denim, is washed to get the final look of the fabric. The majority of washes are developed to mimic the way denim ages naturally when worn, since this process can take years to achieve. And whether the denim garment is a pair of jeans, a jacket or a vest the likelihood that it has undergone some form of wash is very high, although the finish may be a subtle one.
As the name suggests, the stone washing process involves washing denim fabric with pumice stones to create a faded look combined with areas of colour contrast. As the pumice stone rubs against the fabric during the washing process, it removes colour on those parts of the fabric it touches but leaves the untouched parts of the fabric in tact. The longer the fabric and stones are rotated together, the lighter the final colour of the fabric will be.
Acid washing is used to create sharp colour contrasts in denim garments and usually involves dark or indigo denim. This process was patented in 1986 and became popular throughout the 1980s. It involves pre-soaking pumice stones in acid and then washing the denim with these stones so that the acid permeates the cloth in a random pattern. Also known as marble or snow wash, the acid washing process uses chlorine or potassium permanganate as a bleaching agent.
Whiskering is the process used to create lines in denim to mimic an aged appearance. It is particularly used around the crotch and knee areas in denim trousers and around the inside of the elbows on denim jackets to recreate the folding and creasing motion that denim would take on after years of wear. Whiskering, which is also known as "cat's whiskers," is called "knee whiskers" when it is used at the side of the knees and "honeycombs" when used on the back of the knees. On dark denim, whiskering would appear as a lighter colour, while on light denim the whiskering would be darker to create a contrast. Whiskering is created by using sandblasting, machine sanding, laser and hand-sanding techniques.
This process is one of the most common used in denim fabrics and is also one of the most subtle washes. Here the ridges of the denim are rubbed and scraped to create slight fading. This fading generally occurs at the knees, thighs and seat trousers. It is also used on raised areas of the denim such as seams, belt loops and waistbands.