Aluminum acetate is a purified mordant powder that creates bright colors on plant fibers. It is an alternative mordant to traditional tannin mordants. In addition, it is our preferred mordant for plant fibers. Mordanting is an important step in natural dyeing as it helps improve light and washfastness. Its purpose is to provide a bond between the fiber and the dye molecule. Without a mordant bond, natural dye colors will fade, change color and wash out. This is not so desirable after all the hard work of natural dyeing!
We offer instructions for 2 mordant variations: one using aluminum acetate and calcium carbonate (chalk) and the other in combination with cellulose scour. Use percentages of aluminum aetate from 5-10% on the weight of the fiber. Check out our How to Mordant page which provides detailed information on mordanting.
Please note that Aluminum acetate is very powdery and smells like acetic acid, so a dust mask, or respirator and good ventilation is recommended when using it to avoid irritation. It is astringent and may dry hands, so wear gloves to protect skin.
If you prefer to use only tannins for plant fiber mordanting, we offer a list of alternative tannins that may be used for mordanting. Please be aware that tannins will create a different shade than aluminum acetate but these ingredients are also part of a long tradition of natural dyeing and worthy of experimentation.
- 100g of Aluminum Acetate is ample for mordanting 2000 grams (4.4 pounds) of fiber at 5%. The mordant bath may be recharged to save water and mordant. Read about recharging mordants here.