Red onion skins create a earthy range of colors. Protein fibers such as wool and silk, dye a pale to medium nutmeg brown, with a mix of rosewood, russet and rosy browns. Cellulose fibers such as cotton, hemp, and bamboo dye a range of seashell pinks, with a mix of champagne, pale, and silver pink. Natural dye colors are living colors, they are alive with the life that made them.
The dry outer skins of onions can be used for coloring natural textile materials and easter eggs. Red onion skins create a different range of colors than yellow onions skins, so it's important to keep your dye sources separated. The process of achieving color from onion skins is one of the easiest sources of natural color, and is a great place to start if your just beginning with natural dying.
Onion skins are simple for a few reasons, they are easy to source, they are food safe, and they do not require the aid of a mordant to achieve colorfast fabric. I collect my onion skins from a local farm or the grocery store; just ask someone working in the produce department if you can scuffle through the bins and collect the loose skins. Because onion skins are food safe you don't have to get a separate pot for dying fabric, but onion skins seem to be the only exception to that. So if your thinking about experimenting with other dye sources it would be smart to invest in a separate large pot for your dye work. Onion skins do not need a mordant because they are naturally high in tannin, which binds of the color to the fabric, creating lasting colorfast fabrics.
onion skins (the more the better)
water to cover
bring the water to a boil and let simmer for an 1 hour
remove the onion skins from the pot (I suggest using a colander)
soaking the dyestuff a few days before is an alternative or aid in extracting color from dyestuff
evenly soak fibers in hot water before placing them in the dyebath (this helps achieve even color)
place pre-wet fibers into the dyebath
heat dyebath for 1 hour, using a spoon or stick to submerge fibers and free air bubbles
to achieve even color avoid crowding the dyepot
let the fibers cool in the dyebath this will give brighter results
most dye artist let the bath sit and cool overnight or even a few days, longer is stronger
remove the fibers from dyebath, rinse with cold water until water runs clear
hang to dry
It's ok if there is dirt amongst the skins it will be strained out after boiling the skins in water, and it will not affect the color of the dyebath. The more skins you have in your pot the more concentrated your color. I suggest filling the pot over halfway with skins.
Onion skins can be saved for a long time if they are contained and protected from weather.
My 32 quart stainless steal dye pot and adjustable colander
It's best to avoid the direct sunlight when drying fabrics. This helps achieve even dye results and avoid sun bleaching.
There is no better way to get to know the true value of each color than to dye your own, then you will intuitively understand it's emotion.