Folk Fibers Blog

  • Preparing Fabric for Natural Dyes

    An important and necessary step to dyeing fabric with natural dyes is to prepare the fiber for the dye process. Ada and I made a short video sharing our process of mordanting fabric before dyeing. All mentions of "alum" refers to "potassium aluminum sulfate".

    Prepare Fabric for Dye, Step by Step

    1.) Weigh your fabric dry, jot down the number in a notebook. 

    2.) Prepare your fabric by scouring/washing with hot water and detergent, I use synthropal detergent, a neutral detergent. Synthropal removes sizing, dirt and grease on the fabric before dyeing. After dyeing synthropal helps remove excess dye - it's a special detergent for the entire process of dye work! 

    3.) Referring to the weight of the fabric, calculate 15% of the weight of fabric (WOF) this is how much alum mordant you will need to add to your pot filled with water. 

    3.) Dissolve the alum into the water by stirring, then add your fabric to the alum bath. Take your time to unfold and enter the fabric smoothly, if your fabric is scrunched, bunched or folded, these creases and lines will show-up in the dye process. 

    4.) Soak your fabric overnight in the cold alum mordant bath

    5.) The following day, remove the fabric from the mordant and hang to dry on a clothes line. 

    6.) Start dyeing right away with damp fabric, or dry, label and store fabric out of direct sunlight for as long as you need. *Protein fibers such as silk and wool should not be stored longterm, it can breakdown and weaken the fibers. Protein fibers should be used right away for the following day. 

    Note* Mordant procedures for protein and cellulose fibers are not interchangeable, we did not soak our silk overnight, instead we soaked it for only a couple of hours. This was our shortcut, rule-bending, kid-attention-span way to mordant all of our fiber in one pot. 

    You can source alum from local art supply shops or online from dye supply stores, search "potassium aluminum sulfate".  Also, "aluminum acetate" is another type of alum, often the prefered alum mordant for cellulose, or plant based fibers. If your solely focused on cotton, linen, and hemp, it can be worth the extra expense for aluminum acetate, it's helpful in achieving rich color results on plant based fibers. 

    When mordanting silk I soak in the Alum warm, for only for 1-2 hours. When mordanting wool I soak in the Alum cold, overnight or for 24 hours, along with my cellulose fibers.

    Tie off skeins of yarn so they don't get tangled in the mordant and dye bath. Tie it multiple times, every hand length apart, around the skein, in a loose "8". Not too tight or the mordant and dye will not be able to penetrate the fibers evenly and you'll have light or white rings around the yarn - but hey this could be cool if your intentionally trying to achieve variegated colors with knitting or ikat design for weaving! 


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