Best Mordants to Use With Natural Dyes:
There are many mordants you can choose but I believe the following are the best mordants to use when natural dyeing. One of the most important elements of natural dyeing is the use of a mordant or fixative. When dyeing protein fibers such as wool or silk, mordanting
Some of the best and most commonly used mordants and fixatives to use with natural dyes are alum (potassium aluminum sulfate or aluminum acetate) and cream of tartar. When mordanting fibers, it is always recommended to work in a well-ventilated room and wear a dust mask along with an apron and gloves.
To mordant your natural fiber with alum, use about 10-20% of the weight of fiber depending on how deep you would like your color to be. Combine your alum with about a cup of boiling water until the alum is dissolved. Fill your stainless steel dye pot with enough water to cover the fiber you are dyeing, and then add your alum mixture and stir. Now you’re ready to proceed with the dyeing process.
To mordant your natural fiber with aluminum acetate, you should use 5-10% of the weight of fiber. This is about the same as 2-4 rounded teaspoons for every 100 grams of fiber. Add some cool water to your alum to give it a paste-like consistency and then use boiling water to dissolve it. Fill your stainless steel dye pot with hot water, (110-120 degrees Fahrenheit), and add your dissolved alum, stirring well. Now add your fiber to the pot, making sure it’s fully submerged, and stir gently. For about 45 minutes, hold the heat and continue to occasionally stir the contents of your dye pot and make sure you are also pressing on the fibers to eliminate any air bubbles that may form. After 45 minutes, remove your fibers from the dye pot. There is no need to rinse them.
If you’re mordanting cellulose or cotton, you need to fix the alum to the fibers before you’re ready to dye. You can use a calcium carbonate bath to do this, using about 5% of the weight of fiber or 1 rounded teaspoon for every 100 grams of fiber. Add your calcium carbonate to a large container of water that is boiling hot. Add your mordanted fiber to this container and allow it to rest for up to 30 minutes. Once this is done, you can remove your fibers from the mixture and place them straight in the dye pot with no need to rinse in between.
Using Cream of Tartar
Cream of tartar is a fixative sometimes added to alum mordant baths when mordanting animal or protein fibers like wool and alpaca. It is great for brightening shades, improving consistency of color, softening wool, and producing an overall clearer end result in your color. It will also shift the color of some natural dyes such as madder, cochineal, and lac. It is recommended to use cream of tartar at about 5-6% of the weight of the fiber. Just dissolve your cream of tartar separately from your mordant and add it to the pot along with your dissolved mordant.
Please let me know what kind of results you get and have fun!!