It’s winter, and many of us have taken up knitting and crocheting during the cooler weather. While I’m thinking about knitting, my mind wanders to mordanting (of course), and some of the questions we’ve received from curious dyers.
This Mordant Monday, I thought I’d start with some common questions when mordanting changes the hand feel and quality of wool fibers.
The natural dye process uses a lot of heat, and a fair amount of handling: stirring, squeezing, rinsing. It’s easy for wool to react to all of this and become rougher feeling, even felted! Check out this week’s Mordant Monday to avoid the pitfalls and some easy solutions for wool fibers.
Fibers feel different after mordant and dyeing?
The problem
Wool feels gummy, sticky or harsh after mordanting. Fibers feel harsh, look compacted or felted after dyeing.
Possible causes
- A high percentages of aluminum sulfate or aluminum potassium sulfate mordant, meaning above 20-25% on the weight of fiber can cause stickiness or roughness for some wools.
- Mordanting at very high temperatures for prolonged periods can also contribute to fibers feeling rough.
- Highly alkaline solutions can also cause harshness. Avoid soda ash except in small amounts if you use it for scouring raw, greasy wool.
- Agitation and over-handling fibers during the dye process can cause shrinking, roughness and felting with wool and other animal fibers.
- High percentages of iron and high temperatures can cause wool fibers to feel harsh and lead to breakdown.
Solutions
- Lower the amount of alum. We like to use 15% as our normal mordant amount for most wool fibers. Using cream of tartar helps keep wool soft and also helps bind alum more efficiently to wool fibers. Many dyers use between 5 and 7% wof.
- I know many people say simmer your wool, and there’s a good reason for this as wool has scales that open and help bind the mordant. I’ve found that keeping the wool at 195F for 1 hour, and letting it cool in the pot seems to work best for mordanting
- You can experiment with bringing the wool up to 195F and then immediately turning off the heat and letting the fibers cool in the mordant pot as well. Longer soak times may help avoid harshening the fibers.
- Iron as a post-dip uses lower temperatures and shorter dip times.
- Minimize handling and squeezing fibers when they are wet. Also, avoid dramatic temperature changes as this can cause felting.
- Aluminum Triformate is a cold water mordant process for wool, and we’ve had dyers remark that their wool feels much better after using it. We do not use cream of tartar with Aluminum Triformate as the mordant method is much gentler and Aluminum triformate is more acidic than Aluminum Sulfate. We do advise rinsing aluminum triformate well.
Questions
Check out our Mordant Monday archive and our online information!