Making a Purple Dye
Making a Purple Lichen Dyes for Crafts
There are many lichens that can be used to make dyes for natural materials like wool, cotton, silk, dried grass and even wood.
A common one, Oak Moss lichen (Evernia prunasteri), is light-green on the top and white on the underside. It commonly grows on smaller branches of oak, maple and hawthorn trees. In the photo below, the middle branch is turned up so you can see the white underside.
It can be used to make a beautiful purple dye. It's species name (prunasteri) mean prune-colored.
Ecological Considerations:
Be sure to collect only lichens that have fallen on the ground (after a windstorm is a good time to find them) and from the surface of trails so you are not reducing the biomass of material that will be composted. Some lichens also contain nitrogen so we don't want to be removing large amounts of that in one area. Collect from a variety of locations rather than just one. The ones that fall on the trail will be ground up by getting stepped on and not contribute to the biomass on the forest floor. Summer collected specimens usually yield a richer color.
Use a glass jar with a lid that seals.
For wool and silk (and other protein-based materials), fill the jar with an acid bath like 5% vinegar or 100% lemon juice. Wash the wool first to remove oil and salt.
For plant-based materials like grasses and pine needles, ammonia or urine works better.
Try a 1:1 water to ammonia ratio to almost fill the jar. Leave an inch or so at the top as this process needs oxygen. Tightly close the jar, soak lichen but shake daily and open weekly to add oxygen into the process. Store in a dark place where kids and pets can't get at it. Soak for 3 months or more to get a darker more intense color.
Tip: When you open the jar take it outside. The ammonia is very strong and toxic indoors.
Once the liquid turns a dark grape color, it is time to sample it to see if it is the color you desire.
In a stainless steel or glass pot, take one cup of base liquid (seiving out the lichen) and dilute it with 4 cups water. Add one ounce of wool or materials to be dyed and bring the boil then simmer for one hour. Remove from heat and cool.
Remove the wool from the dye bath and air dry it. If you like the color, remove the lichens and use the dye as is. If you want a darker color, leave the lichen in the liquid, close the jar and store it for longer, continuing to shake it weekly. The longer you leave the base liquid in the jar with the lichen, the darker the color will be to a point. Storing temperature, light levels and material being dyed can all affect the color.
Experiment with what color intensity you want. Put more wool in for a lighter color and less wool for a darker color.
If you reuse a batch of dye, some color intensity will be lost each time you reuse it.
Mordants (mineral salts) are not needed to get more intense colors and in fact, may decrease the color. Colorfast is not needed for this type of dye as it is quite permanent.
The base dye (after removing and carefully disposing of the lichen) can be stored up to a year for re-use in other projects.
Be patient! Have fun!
