Definition of Stonewashed
tr.v. stone·washed, stone·wash·ing,
stone·wash·esTo wash (garments or material, usually denim) in
large industrial machines with pumice pebbles to soften and abrade the
material by friction.
that have been treated to produce a faded, worn appearance. This is
usually accomplished either by washing the jeans with pumice
in a rotating drum, or also by using chemicals to create the appearance
without the use of a rotating drum. The expanding cost of importing pumice
stone from Italy, Greece and Turkey lead to extensive mining of pumice
deposits in California, and Arizona and New Mexico, triggering a negative
response from U.S. ecologist groups.
Reducing pumice usage and the growing disposal of its chemically tainted
residue, triggered a search for novel methods, notably the use of
alternative abrading materials or machines and the use of cellulase
enzymes. Stonewashed jeans were a popular 1970s fashion trend, before
commercial acid wash denim was introduced in the 1980s.
In the 2000s, stonewashed jeans were heavily distressed, with pre-made
holes, frayed edges and extensive fading caused by sandblasting.
Claude Blankiet with
American Garment Finishers from Texas promoted the use of cellulase
enzymes in the finishing industry.
Cellulase was already used in the paper pulp, food processing industry and
currently in the fermentation of biomass for biofuel production. Cellulase
is produced primarily by fungi, bacteria and protozoan that catalyze the
hydrolysis of cellulose. Since the enzyme decomposes cellulose fibers this
enhanced the characteristic appearance that the jeans have been abraded
with stones (and eliminated or considerably reduced the usage of natural
pumice stones). Selecting the most suitable type of enzyme and their
application for ageing jeans was the key to success. American Garment
Finishers used a new cellulolytic agent patented in 1991 by Novo Nordisk
because of its safer effect on cotton fiber. Other finishers used an acid
side Trichoderma fungi enzyme, cheaper and faster acting, but resulting in
excessive fabric tear and a back lash because jeans pockets were lifting