Plants have been used for thousands of years to make natural dyes. Onion skins are one of the best natural sources. They produce lovely, easily-extracted colors. The dye is absorbed well by the fibers without a mordant (a fixative or binder), which is usually required when using other botanicals for dyeing. Onions are readily available all over the world—all you need is the papery, outer skins. Some grocers will even give you the leftover skins at the bottom of their bins. When using onion skin dye, natural fabrics are the best materials to color, including wool, hemp, cotton.
Equipment / Tools
- 3 Non-reactive metal pots
- Stainless steel tongs
- Mesh strainer
- Heat source
- Water source
- Clothesline or drying rack
- Natural yarn, fiber, or fabric
- 10 Onion skins, red or yellow (the more you have, the deeper the color)
Saturate Fabric in Water and Set to Simmer
Add enough water to your pot to thoroughly wet your material and allow it to float freely in one of the containers. Heat the water slowly, bringing it to a gentle simmer for about 20 minutes. At the same time, in a separate pot, get the skins started.
Boil and Simmer Onion Skins
Fill another pot with about three times as much water as skins. The skins should float freely. Make sure that there is enough water for the fabric or fiber also to float freely once you add it later. Put the lid on. Bring the bath to a boil. Turn it down and simmer the skins in the water for an hour.
Periodically Check the Color
As the onion skins are boiling, carefully lift the lid of your pot, allowing the steam to escape and check on the color. More prolonged boiling will release more dye, but only to a point. If you want a lighter shade, check more frequently (10-minute increments).
Strain Out Skins and Add Fabric to Dyebath
Place the mesh strainer over another pot, strain out the skins, and discard the skins. The reserved liquid is your dye. Set the dyebath to simmer. Once it's simmering, put the wet fabric in the pot. Simmer for 30 minutes.
Turn off the heat after 30 minutes. Using tongs, remove the fabric from the bath and place it into an empty pot or container to cool down.
Rinse Fabric and Dry
Once it's cool enough to handle, rinse the fabric in fresh water. A special note with wool: Rinse it with water that's the same temperature as the fabric. For example, if you have hot wool, use hot water. It will prevent felting, which can make the material more coarse. Hang the fabric up to dry on a clothesline or portable drying rack that is not in direct sunlight.
While fixatives or binders are not necessary for onion skin dye, you can use a mordant (a bath in a solution of water and alum) to ensure colorfastness. And, to change the onion-dyed fabric to green, dip the dyed fabric into an iron mordant solution.
You can substitute other non-toxic plants, such as yellow and orange marigolds, cosmos, or coreopsis, for the onion skins. These flowers yield yellow, gold, brown, and reddish tones similar to red and yellow onion skins.