Snow wash jeans were just one of the 80s fashions you parents were never going to understand. Why buy jeans that were faded before you even got them home? Just like, why woud you buy ripped jeans? Because they were cool, that's why!
To get the snow wash of 'acid wash' effect, a chemical was sprayed onto the material then quickly removed. Originally, the 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 marinated pumice stone in it and then vacuum packed the stone to the required moisture level. It stripped the top layer of colour off to a white surface with the undertones of navy blue remaining in the jeans.
The really fashionable among us also had a snow wash jacket to wear with our snow wash jeans. Oh yes! The double denim effect. In the late-80s, snow wash was taken a step further when red styles and black (black and gold acid wash) came into the mix.