Scour, Mordant, and Color Changers
When working with natural dyes, first pre-wash the goods you would like to dye, also known as scouring, to remove any excess dirt, wax, or starch. Then, mordant the goods. The mordant, once applied to the goods, acts as a binder, which the dye attaches to. The mordanting step in the natural dyeing process allows for the widest range of color and the best light-fastness.
Note: it is important to scour goods before indigo-dyeing, though you do not have to mordant them.
- cellulose-based fibers, use soda ash.
- protein-based fibers, use ecover or dawn - found at your local grocery.
- cellulose-based fibers, use aluminum acetate and either wheat bran or chalk.
- protein-based fibers, use aluminum potassium sulfate.
Iron is used primarily on cellulose-based fibers to shift colors greyer and darker. For instance, yellow shifts to green, pink to purple, etc. The application of iron can increase colorfastness. And can also be used as a mordant.
Tartaric acid which is similar to cream of tartar can be used to shift the pH of a dyebath which can affect the color. For example, use tartaric acid with cochineal and get pink. Skip this step and get purple.
To learn how to use scour, mordant, and the other things listed on this page, pick up a copy of our book, The Modern Natural Dyer.
To purchase natural dyes, click here.
To purchase indigo, click here.