Protein fibers include all fibers obtained from animals, such as wool, angora, mohair, cashmere, and camel's hair; they also include the insect-derived fiber, silk.
Proteins are made out of different combinations of the twenty essential amino acids. They are more complex than cellulose, which is made out of repeating units of a sugar, glucose, and thus there are more ways in which different dye chemicals can attach to them. There are, therefore, many more different substances which can be used to dye protein fibers.
All animal hair fibers, such as wool, are sensitive to high pHs. You will understand this intuitively if you have ever tried to wash your hair with a high pH bar soap, instead of the special pH-balanced detergents sold as shampoos! To dye wool, you must avoid the high pH of the soda ash recipes used to dye cotton. Most wool-dyeing recipes call for an acid such as acetic acid, white vinegar (which naturally contains acetic acid), or citric acid.
Silk is an animal fiber, made of protein, but it is less sensitive to high pH than animal hair fibers are. It can actually be dyed quite well with the same soda ash recipe used to dye cellulose fibers with fiber reactive dyes. The high pH tends to soften silk and remove some of its luster. Silk can also be dyed with all of the dyes that are used for wool.
Dyes for Protein Fibers
Acid Dyes
Acid dyes are the most popular dyes used on wool, and comprise a very wide range of different dyes. Some of the many different available acid dyes include food dyes, Washfast Acid dyes, Acid Leveling dyes, and One Shot dyes. For more information on acid dyes, see About Acid dyes.
Fiber reactive dyes more commonly used on cellulose (cotton etc.)
Information on how to use fiber reactive dyes such as Procion MX, Cibacron F/Sabracron F, and Drimarene K as acid dyes for protein fibers
has been moved to a new page on Reactive dyes on protein fibers.
Natural Dyes
Many natural dyes work very well on protein fibers, such as wool. Most will require a mordant, such as alum, copper, tin, or iron. See the page, About Natural Dyes.
Lanaset Dyes
The longest lasting, most wash-resistant, richest of hand dyes available for dyeing wool in the US are the Lanaset/Sabraset/Telana dyes. Unlike other dyes for wool, Lanaset dyes can be washed in hot water without fading badly. They are often difficult to obtain other countries in quantities small enough for hand dyeing.
Vinyl Sulfone Dyes
Vinyl sulfone dyes (vinyl sulphone, if you are British), also known as Remazol dyes after the trademarked name under which they were first introduced, are a type of fiber reacfive dye that is often used in silk painting. They are fiber reactive dyes whioch will react with cellulose at high pH, or with protein under hot acid conditions. Unlike other fiber reactive dyes, they contain a masking group which protects the reactive portion of the dye from reacting with the water in which the dye is dissolved, so these dyes will stay good for quite a long time after being dissolved in water, and are customarily purchased as liquids. The masking group can be removed from the dye under hot acid conditions, after which the dye will react with a protein fiber. Both steps may be accomplished by simmering wool with the vinyl sulfone dyes for 45 minutes; see Vinyl Sulfone Fiber Reactive Dyes.
Basic Dyes
Wool can also be dyed with the same
Basic dyes that are used for acrylic fibers; the colors can be very bright, but the lightfastness is very poor, and the toxicity of the dyes is sufficiently significant that they should not be used in a home kitchen, but restricted to use in a dye studio or lab in which eating is never allowed.
Vat Dyes
Vat dyes, such as indigo, can also be used to dye wool and other protein fibers.
All purpose dyes
All purpose dyes can be used to dye protein fibers, because they include an acid dye in their mixture. See All Purpose Dyes.