Name: Mara
Message: I was looking for information on dying with natural dyes, but on silk. I know you can get silk scarves at Dharma Trading, and I was curious about dying with tea, coffee especially, blueberry (and any other berries), etc. (things that normally stain quite excellently), and how to fix those so they don't fade out. A lot of people's sites cover cotton, wool, linen, but not silk. One site had a lot about dying with coffee and tea, but recommended vinegar (it was the only one) and I noticed you didn't recommend that. Do I boil silk, or not? What kind of fixer do I use for these kinds of natural stain/dyes? I'm not a dyer, and the internet is such a great wasteland of incomplete information, but you seem to know a great deal about dying. Help?

Silk is easier to dye with natural dyes than cotton is, though wool may be easier still. You can use the same dyes for silk as for wool, since both are protein fibers.

The general rule in natural dyeing of silk is to simmer the (pre-mordanted) fabric, at 180 degrees F, or 82 degrees C., with a double or greater weight of dyestuff, for at least an hour; e.g., for one pound of silk, use at least two pounds of dye material. Silk requires twice as much dye as wool, for a given depth of shade. Silk should not be boiled.

For a fixative, use a mordant to pre-treat the silk. Most natural dyestuffs require that you first mordant the fabric with metal ions; alum is the one metal mordant that is not hazardous to work with. Different metals produce different colors from each natural dyestuff, but some of the commonly used metals, such as chromium which helps to make lovely colors, are extremely toxic and bad for the environment. Tea is one of the few exceptions to the rule of requiring a mordant, since its coloring matter is tannin, which can sometimes itself act as a mordant. Acid does improve the color when dyeing with fruits, but won't do anything for tea; the mordants recommend by Jill Goodwin for coffee are either alum plus cream of tartar to get browns, or iron to get greys.

Along with a great deal of other useful information on natural dyeing, there is a good recipe for using alum to pre-mordant silk in Jill Goodwin's book, A Dyer's Manual, which is available internationally for 18 pounds, postage paid, from its own website; if you order this book, take care to buy the improved 2003 second edition, as the original 1982 first edition, sometimes available from used bookstores, is dangerously skimpy on the hazards of mordants. Amazon sells used copies of the first edition for much larger sums of money, but the second edition is greatly to be preferred. Many different natural dyes are covered in this book.

Not everything that stains makes a good natural dye. For example, beets seem like the perfect red dye, but actually tend to produce a boring tan or a soft yellow. You can have a lot of fun experimenting with this, though a good guidebook will save you some pointless exercises. For information on natural dyeing, books are generally much more useful than online sources of information. If you want to purchase natural dyestuffs and mordants, one good source is Aurora Silk.