What’s the difference between the two? And what’s the procedure in stone-washing as opposed to acid washing denims? Let find out the basic process for each.
– As the name implies, freshly dyed jeans are loaded into large washing machines and tumbled with stones. Adding pumice stones gives the additional effect of a faded or worn look.
– The pumice abrades the surface of the jeans like sandpaper, removing some dye particles from the surfaces of the yarn. Pumice has been used since the introduction of stone washed jeans in the early 1980s.
– However, stone washing with pumice has some severe drawbacks. The quality of the abrasion process is difficult to control:
- Too little will not give the desired look.
- Too much can damage the fabric, particularly at the hems and waistbands.
- The outcome of a load of jeans is never uniform, with a significant percentage always getting ruined by too much abrasion.
- The process is also non-selective.
- Everything in the washing machines gets abraded, including the metal buttons and rivets on the jeans as well as the drum of the washing machine. This substantially reduces the quality of the products and the life of the equipment, and increases production costs.
– The process was a form of chemical bleaching that broke down the fiber of jeans, forcing the dye to fade and creating pale white streaks or spots on the denim.
– At first the Acid Wash process involved soaking pumice in Industrial Strength Chlorine however is was discovered that potassium permanganate was more controllable and just as strong an oxidizer.
They simple(sic) marinated pumice stone in it and then vacuum packed the stone to the required moisture level. Acid wash was a chemical processed denim that stripped the top layer of color off to a white surface with the undertones of navy blue remaining in the jeans. And not only jeans were acid washed; if you were truly fashionable, you also had an acid washed denim jacket that matched said acid washed jeans.