Name: E. May

Message: First I would like to thank you for such a wonderful site.  I often refer people to it when asked in forums about dyeing with kool-aid or why acrylic won't dye with kool-aid and what to use to dye acrylic.

You seem to know about the makeup of wool and chemical reactions.  Is there some way to make my own superwash wool?  I really want to try it but can't seem to find any information.  I would really love to know this answer but understand if you can't find the time or don't know.

Superwash wool is created in a surprisingly toxic way. There are several different processes that can be used to make Superwash wool, but all of them start with its chlorination by caustic chlorine-based chemicals. I don't think it's a good idea to consider working at home with these chemicals, because they can cause burns and, under the conditions used, can easily produce deadly chlorine gas.

The hypochlorite often used to chlorinate Superwash wool is similar to the active ingredient in household bleach, but it is more dangerous because it is unstable under the acidic conditions used. The sodium hydroxide (caustic soda or lye) that is normally added to household bleach keeps the pH high so that chlorine gas will not be produced, which makes it safer to use. However, the high pH of sodium hydroxide would destroy wool. Wool is very sensitive to high pH and does best if kept at mildly to moderately acid conditions. This is why we never dye wool in the presence of soda ash, which is widely used to dye cotton; although wool takes, for example, Procion MX dyes very well when dyed with soda ash as the auxiliary chemical, the amount of damage is considerable, so it is preferable to dye wool using a mild acid, instead.

After the wool is chlorinated, it is washed and the chlorine is neutralized, after which a patented synthetic resin coating is applied, essentially gluing down the scales that would otherwise interact under the mechanical stress of washing to produce felting. I don't know of any source for this product for home or studio use.

It is surprising that, after all of the chemical changes produced in wool by the Superwash process, the wool remains very easy to dye. Superwash wool is an excellent material for dyeing at home with acid dyes. I have never heard of any harm whatsoever that might be done to anyone by Superwash wool, as compared to natural wool, and yet I suspect that it might be less popular if more people knew what the treatment entails. In some respects, it may not be entirely correct to refer to Superwash wool as a natural fiber.

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