• Oh, Shift! Using pH Adjustments to Extract Pigment and Modify Colors From Madder

    Some natural dyes are more sensitive than other to changes in pH. Both species of madder that I have been using recently, Rubia cordifolia and Rubia tinctoria (or tinctorum) fall into that category. In this post, I am specifically talking about Rubia cordifolia (RC), which is the species that grows in India and is widely used around the world today, though its historic uses stem from India, Africa, and, later, Europe. I started out with two different batches of RC. One appeared a golden yellow, almost like turmeric, when it arrived. The other appears more of a dark terra cotta color. Since the yellow one was already opened for a…

  • Soak ‘Em if you got ‘Em: Adventures in Mordant

    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…