Choosing and using mordants is a really broad topic, so I will be talking about it in chunks. In this segment, I’m talking specifically about the mordanting I did in preparation for dyeing silk and cotton with madder dye. For the sake of simplicity, let me start at the beginning. What is a mordant and why do we need it? The word mordant is related to the French word morder, “to bite.” A mordant is a substance that helps the pigment in the dye “bite” into the fiber and hold on. Dyeing fiber is a process of creating a molecular bond between fiber and pigment, and many natural dyes can’t make…