Playing with pH in Botanical Dyes

Gather around… Today we are dipping a toe into the world of chemistry by experimenting with modifying the pH of natural dyes! Natural dyes are known for being very sensitive to changes in pH, which is why if you’re wearing something that is naturally dyed, you want to avoid getting any lemon juice on it because it can change the color.

Today, I have two types of dye: pomegranate rind and madder root. I have mordanted all of my samples with alum acetate and then dyed one piece of fabric in a pomegranate rind dye bath and one piece in a madder Root dye bath. After I dyed the fabric, I cut it into smaller swatches and then dipped each swatch into a cup of water with a spoonful of pH modifiers.

The modifiers I used are ferrous sulfate, soda ash, citric acid, chalk, a.k.a. calcium carbonate, and cream of tartar. The most obvious change is the Ferrous sulfate made the color much darker. The citric acid made it much brighter and lighter. The madder seems to be more sensitive to the pH shift than the pomegranate.

It’s really fun to experiment with ways to expand the range of color by shifting the pH. I’ll be teaching a class where we will experiment with this method at the Ann Arbor library this Saturday, November 15 from 1 to 3 PM. The class is completely free and there is no registration required nor is there a payment of any time required!

If you want to join just come on by! If you want to hear more about my upcoming classes join my email newsletter :-)