Aluminum Sulfate

Description

If you are looking for a less expensive alternative for mordanting, consider aluminum sulfate. This mordant contains the same active ingredient (alum) with a different refining process as aluminum potassium sulfate. It has more irregular-shaped granules (called kibble) that produce near identical results. It is a wonderful mordanting material for protein fibers such as silk and wool. For detailed instructions, please see our how to page.

We love that these dye baths may be used either hot or cold, and may also be re-used with the addition of more alum. This allows the dyer to use less energy and conserve more water. Check out our blog post entitled Using Less to Get More for more information about reusing alum baths.

From our Feedback Friday series:

When you refer to alum, do you mean aluminum acetate or aluminum sulfate?
The common term for “alum” means aluminum sulfate.

What is your favorite/preferred mordanting process for plant-based and animal-based fabrics?
Check out our mordanting instructions. I am partial to aluminum sulfate with or without Cream of Tartar for wool and animal fibers, aluminum sulfate for silk, and aluminum acetate for plant-based fabrics.

When I use a plant dye on my all natural wool yarn, I frequently end up with a duller looking yarn than I started with. The color looks flat and the slight sheen that the yarn had previously, is gone. Could it be my mordant? I use 12% Alum and 6% cream of tartar based on the wof.
It’s possible that you are using a bit too much alum for your water. Sometimes excessive alum will make the fibers a little rougher, or tacky when using hard water. As well, the yarn appears slightly “cottony.” Try using about 8% alum and 5% cream of tartar and see if the yarn quality improves.