How to Choose Between Natural Dyes or Acid Dyes
How to Safely Use Acid Dyes
Natural dyes have been used for centuries creating color from plants, insects, fungus, and minerals. Certain colors denoted higher social classes and wealth because they were harder to obtain. In contrast, acid/synthetic dyes are a recent development from the mid 1850s.
Choosing natural or synthetic dyes can be confusing to new dyers. There are pros and cons to each method and certain precautions should be taken no matter what type of dye material you choose.
What are Acid Dyes for Wool or Protein Fiber
Synthetic acid dyes come in a wide range of colors and are easy to use. They are vivid and can be more closely duplicated. The dyes can contain heavy metals that might be toxic. It’s important to read the information provided by the manufacturer before using the dyes. Acid dyes form a covalent bond with protein fiber in the presence of a mild acid. Vinegar or acetic acid are commonly used for this. Follow the directions carefully when mixing the dye. I prefer to use grams as a measurement for both the dye powder and the weight of dry goods to be dyed.
Step-by-Step with Acid Dyes
The following is a general description of how to use acid dyes. Your method may vary and the manufacturer’s recommendations should be followed. Begin with skirted, scoured fiber or clean yarn that has been washed to remove any sizing. Weigh the dry fiber and make a note of the weight in grams. If you choose to use ounces, use ounces for all weights.
The dye powder container will have a recommendation for the amount of dry dye powder per pound of yarn. For simplicity, we will use one pound of fiber. One pound is equal to 16 ounces or 453.5 grams.
Now, when you know the weight in grams, you can easily convert the percentage of dye based on the instructions. If the dye recommends two percent dye powder per weight of goods to be dyed, that would be nine grams of dye per pound.
Begin to Dye with Acid Dye
Add the dry dye powder to a half cup of water to form a paste. Slowly add more water to dissolve the dye.
Next, add the dissolved dye to the dye pot of water. The dye pot should have enough water in it that the fiber can move freely and not be stuffed into the pot.
Begin to heat the water.
Wet the material to be dyed. I like to use mesh laundry bags for dyeing fleece because it makes it easy to handle.
Add a half to two cups of vinegar to the dye pot according to the manufacturer’s directions.
Add the wet fiber.
Continue to raise the temp of the dye bath. When it reaches 180 to 190°F, hold the temperature at that point for 30 minutes. Do not let the liquid boil as you could end up felting the wool.
Check the dye bath after 30 minutes at 180°F. The water should be mostly clear and the wool should be the color you desired. If not, continue to heat for a few more minutes and recheck. Occasionally, not all the dye will absorb.
Turn off the heat and let the dye bath cool. Carefully remove the fiber and set it on a clean surface to drain. It will be extremely hot so use protective gloves when handling. When the fiber is room temperature, rinse in similar temperature water until the water runs clear. Squeeze out extra water, but do not twist or wring or you might felt the fiber. I like to lay the fiber on large racks to air dry.
Cleaning Up Acid Dyes
Heavy metals such as chrome or copper have toxicity cautions. The dye containing these metals should not be disposed of in the water supply or sewers. Pouring them into gardens and lawns is not a good practice either. Careful measurements when preparing the dye bath should result in most or all of the dye being bonded to the protein fiber. The water is left clear when this happens. Acid dyes can be brought to a neutral state by adding baking soda before disposal. PH test papers are helpful to have on hand to determine the pH of the dye bath. When in doubt, the manufacturer should have posted instructions on safe disposal. Some dyes may need to be stored in plastic jugs until a community clean up day is held.
Natural Dyes for Wool or Protein Fiber
The steps used when dyeing with natural dyes are somewhat different. First, you have to source the dye material. These can be purchased from various dye suppliers or you can find the material in nature.
Starting the Natural Dye Process
The first step for most natural dyes is a mordant bath for the fiber. You can do this ahead of making the dye bath or the day you plan to dye. The longer the fiber sits in the mordant bath the better. I use a 12 percent solution of alum in water. If you choose to mordant fleece or yarn ahead of time and let it dry for storage, just wet the wool before dyeing. There is no need to redo the mordant bath when dyeing wool yarn or fiber.
Each raw dye material will have slight variations used to make a dye bath. If using dry powdered natural dyes, follow the instructions on the label. The dry powdered dyes are concentrated forms of the raw materials.
Onion skins make beautiful yellow and gold dyes and are easy to save for a dye bath. Using onion skins as an example, collect enough dry onion skin to equal 10 percent dry weight of the fiber. For example, 16 ounces of fiber would require 1.6 ounces (45 grams) dry onion skin. (Note* some dyers use as high as 50 percent weight of onion to dry fiber. I prefer a softer shade of yellow and have cut back to 10 percent with good results. Other dyers will simply say “more is better” for the amount. )
Onion has natural tannins so mordanting is not always necessary. However, you can still dye the wool if you did mordant the fiber.
Step-by-Step Natural Dyes Procedure — Onion Skin
Using a stainless steel stock pot cover the onion skins with fresh water. Bring to a simmer for one hour. Alternative methods using no heat, leave the onion skins soaking in the water for a few days. This is a good dye to practice the solar dyeing wool procedure. After heating, you can leave the onion skins in the pot overnight for richer color.
Strain the onion skins from the dye liquid.
Wet the fiber to be dyed.
Push it into the dye pot using a long handled spoon. Do not stir and agitate or you risk felting the fiber.
Bring dye bath to a simmer just below boiling.
After one hour, turn off the heat and allow the fiber to cool. You can leave the fiber in for a few hours or a few days for stronger color. Remove from the dye pot. Squeeze out extra water, but do not twist or wring. Then, rinse well in lukewarm water until no color runs from the fiber. Hang to dry or dry flat on a rack.
Cleanup for Natural Dyes
Exhaust bath dye is using the color that is left in the dye pot until no color remains. Doing this is one way to achieve shadings of the same color family. Since plant dyes are natural, disposing of them is simple. There are a few that I won’t pour on my gardens, such as black walnut or pokeberry. For the most part, any excess dye liquid from natural dyes ends up watering my garden.
With both natural dyes and acid dyes, use protective safety gear such as rubber gloves and a mask. Use only stainless steel pots reserved for dye projects. Residue from some dyes can still be present and therefore, you don’t want that in your food preparation cookware.
Do you prefer natural dyes or acid dyes? Let us know why in the comments below.