JOHN MARSHALL:
works in fabric
MORDANTS
In the context of how the word will be used in this text, mordanting is adding a substance to the dye source to influence it, that is to bringing out characteristics that may be otherwise hidden or suppressed. That substance is the mordant. A mordant does not serve as a color source of its own.
Containers other than glass or stainless steel may also be used, and the metals from which they are made may be employed to exert an influence on the ultimate color of the dye in the form of a mordant.
Mordants are commercially available, commonly in the form of salts from metals such as tin, chrome, iron, copper, and aluminum. These mordants are listed in descending order of relative toxicity: chrome, tin, iron, copper, and aluminum. Aluminum salt, also known as alum, is used in making pickles, etc., and may be purchased in most grocery stores. Other items I will lump into this category of mordants are cream of tarter, baking soda, and vinegar. The later two serve to change the alkalinity and acidity, respectively, of the dye another property that influences the final color.
Tannin is commonly found in many plants and can function as a mordant. It can also be purchased through chemical and dye supply stores in a more refined state as tannic acid.
When using commercially prepared mordants
take care with how you use, store, and dispose of them. Remember,
many of them are toxic, especially if allowed to build up over
a period of time. The methods presented below of applying the
dyes with brushes allow for less waste and therefore fewer toxins
released into the environment.
As mentioned above,
there are alternatives to using commercially prepared mordants:
After preparing your dye liquid, allow it to sit for an extended
period of time in a vessel made from the mordant you seek: an
old cast iron pot, a copper jug, etc. To change the acidity of
your dye try using citrus fruit, such as limes, instead of vinegar.
Your results may not always be predictable, but your work will
never become monotonous!
Most dyers mordant the cloth and then apply the dyes as two separate steps. The advantage is that the mordant has a chance to "bite" into the fiber, so that when the color is applied, a maximum amount of bonding takes place.
I prefer to first dissolve a very small quantity of mordant in warm water. Then, after approximating how much dye I will need for one coat, add this mordant solution to my larger container of dye.
By adding the mordant solution a little at a time to the dye, you can actually watch it change color. Once you can see a change in the color of the dye there is no danger of adding too little mordant. Too much mordant will tend to take most colors to a brackish tone and will also tend to weaken the fiber in the long run.
Test the dye color on the selvage of your sized cloth by applying a little with a small brush and allowing it to dry. You may speed up the drying process with a blow dryer.
Now that you have the desired color in sufficient quantity for one application and you are ready to brush it on the cloth. But before doing so you should increase the volume of your dye by the actual number of coats you plan to apply. Plan on a minimum of two to three coats. Add room temperature water to the dye solution to increase the volume. Once all three coats have been applied, the color should have the same depth as the original test color.
If you find the right color with your dye/mordant mixture, but would like a darker shade, adding more mordant alone won't help. Either add a greater concentrate of dye, with more mordant; or (assuming you have a sufficient volume of dye solution) plan on applying extra layers until you have the desired character.
I prefer not to carry mordants for resale.
To order commercially prepared mordants I recommend contacting Earth Guild at:
Earth Guild
33 Haywood Street
Asheville, NC 28801
1-800-327-8448