Monday, December 04, 2006

Tannin as a Mordant Recipe

There are two types of fibers from what I can gather.

  1. Vegetable fibers, also called cellulose fibers such as cotton - this is the type of fiber that most basketweavers use. So most recipes are given for both cotton and wool, so when choosing take the cotton recipe.
  2. Animal Fibers, also known as protein fibers, such as wool - although I've read that any dye that will work on Wool will also work on Vegetable fibers.

Tannin is usually used on all Vegetable fibers because it helps either the mordant of Alum or any of the others adhere to the fiber better. Tannin can be used as a pre-mordant or alone as a mordant but most of the sources suggest using the Tannin first or also in the all in one dye method for best results on all vegetable fibers.

The earliest and richest source for Tannin was in the Gall Nuts of oak trees. They were produced by insects who would deposit their eggs in small punctures they made on young branches.

Other sources of Tannin were the barks of alder, chestnut and oak, each has a varying percentage of tannin.

Tannic acid is still used in some types of dyeing and medicines.

The recipe:
  1. Dissolve 1/2 ounce (light colors) to 1 1/2 ounces (dark colors) of tannic acid in 4 to 6 gallons of hot water (130 to 170 degrees) in a nonreactive pot (I use a small stainless steel pot). An Iron pot will produce a grey, black or a dull color from the tannin.
  2. Place the fiber in the tannin solution and steep for 8 to 24 hours; Do not heat the bath again; in fact, cotton mordanting occurs well at room temperature, remember cotton is most like the fibers basketweavers use;
  3. Remove, rinse once and dry;
  4. After it has dryed then do your other mordant if desired or place the fiber into the dye pot.

Although Tannic acid is the best tannin source for bright and light colors, it may not be available in which case tannin-bearing plants will work as well.

For 1 ounce of Tannic acid you can use:

  1. 4 ounces dried or 8 ounces fresh sumac leaves and shoots
  2. 2 ounces cutch extract or tara powder
  3. 10 ounces oak galls
  4. 18 ounces myrobalans or
  5. 14 ounces divi-divi (I have no idea what that is....:))

I used the tara powder which is about 50% tannin, I added 1/4 cup to a gal of water and then added 1 coil of cane and leave it sit overnight. Depending on the tan color achieved, it will mordant several coils of cane. Once the color reaches a light tan the Tara Powder has been used, so you will need to make another batch to mordant more cane if you desire.

If you use Tara Powder put it in a nylon stocking to prevent the residue from floating around in your solution.

Many sources will tell you that a pre-mordant to a cellulose fiber will make the dye adhere better to the fiber and prevent fading of the natural colors.

1 comment:

goatsfoot said...

Hello :) Animal fibres are substantially different, being protein, and take different mordants, and often, different dyes, or at least yield different shades from plant fibres.

The divi-divi is a Central America (-ish) legume tree (Caesalpinia coriaria), whose green pods yield tannins. Your post reminded me that there's one in my local Botanic Gardens, so I must check it for fallen pods when ripe.