Mordants Define Color In The Natural Dying Of Wool
What are mordants? They are usually heavy metal ions which allow the natural dyes to remain permanent. Mordants remain in the fiber, permanently holding the dye; each mordant creates different colors in each dye bath. Be aware that some metals, such as chromium and tin are extremely toxic. Others, such as copper and iron can be dangerous if misused. Alum, being the most popular mordant, is less toxic but can be an irritant and poisonous if ingested. Also, it is important to note, excessive quantities of mordants are damaging to the fibers. Given this information, do be careful when setting out to begin the task of mordants.
When naturally dying your wool for weaving or knitting, it is important to note that using different mordants will affect the intended dye color. The resulting colors are different, but will inevitably blend nicely together since they all use the same natural dye color. While some dyes are more successful with one mordant or another, they can inevitably accentuate the colors in combinations.
For every wool bath you prepare, you would usually test the color on the similarly numbered skeins of wool, each mordanted in a different solution. It's best to divide your dye in four separate pots, and four equal portions in order to properly distinguish the color outcome. In the dye preparation, use one pound of vegetable matter to dye one pound of wool. This is a common rule for all to follow.
The following four mordants used for this exercise are to be used to mix with each pound of wool.
Tin: ½ ounce stannous chloride plus 2 ounces of cream of tartar.
Iron: ½ ounce of ferrous sulfate plus 1 ounce of cream of tartar.
Chrome: ½ ounce of dichromate of potash.
Alum: 4 ounces of alum (potassium aluminum sulfate) plus 1 ounce of cream of tartar.
Note: If you are using iron, boil the wool in the dye for a half of an hour, then remove it, stir in the ferrous sulfate and cream of tartar, replace the wool, and boil another half hour. The other mordants are done in advance of dying.
Here are some varied examples and results you can achieve with four different natural dye baths and four different mordants.
Figs: Create tones of yellow. Use the fresh younger leaves. Tin will give you the brightest color, chrome will create the dullest.
Rooibos: Creates tones of yellows and browns. Using the freshly cut living bark is best because dried bark gives duller tones. Iron gives a deep rich brown and the other mordants create a rich brownish yellows.
Logwood: Creates tones of yellow, brown and black. Alum gives a duller yellow, but it blends really well with other colors, such as iron creates a black, tin creates a nice grey and chrome creates a deep rich brown.
Hibiscus: Creates tones of browns, grays and yellows. Use only the flowers, dried or fresh. If the stalk or stem is used an olive green color is the result. Tin creates brown, iron creates many shades of lavender to dark purple, then to gray. Chrome and alum create tones of yellow with similar effects.
Walnut: Creates tones of warm browns. Use the dried husks for best results. Tin, iron and chrome used together will create dark, medium and light browns. Adding logwood chips creates a beautiful rich dark brown.
