Mordants and Additives

Mordants are needed to set the color when using natural dyes. Different mordants will give different results.

Alum: (Aluminum Potassium Sulfate)
This is the most widely used mordant. Be careful not to use too much with wool, otherwise you will get a sticky feeling that doesn't come out.

Copper: (Copper Sulfate)
This mordant is used to bring out the greens in dyes. It will also darken the dye colors, similar to using tin, but is less harsh.

Citric Acid: Used in natural dyeing to increase acidity of dye baths. Also used in place of Acetic Acid.

Iron: (Ferrous Sulfate)
Dulls and darkens dye colors. Using too much will make the fiber brittle.

Glauber's Salts: (Sodium Sulfate)
Used in natural dyes to level out the bath. Also use in chemical dye.

Spectralite: (Thiourea Dioxide)
This is a reducing agent for indigo dyeing.

Synthrapol: Use before dyeing to uniformly wet-out, without raising suds, improves your dye results significantly.

Tartaric Acid: A must for cochineal. This mordant will expand the cochineal colors.

Tin: (Stannous Chloride)
Tin will give extra bright colors to reds, oranges and yellows on protein fibers. Using too much will make wool and silk brittle. To avoid this you can add a pinch of tin at the end of the dying time with fiber that was pre-mordanted with alum. Tin is not commonly used with cellulose fibers.

Washing Soda: (Soda Ash / Sodium Carbonate – hydrous) Used as a fixative for reactive dyes.

If you don't find exactly what you want, or would like a mordant recommendation, please call the shop directly at 800-441-9665 or contact us for assistance.