Alum

Choosing Among Alum, Iron, Copper and Tannin: A Practical Guide to Traditional Mordants

This guide compares four traditional mordants—alum, iron, copper, and tannin—explaining their unique effects on protein and cellulose fibers to help natural dyers achieve predictable colors. It highlights the crucial role of tannin as a pre-treatment for cellulose fibers to ensure lasting dye adhesion.