We get mordant questions all the time at Botanical Colors so why not create Mordant Monday??? Got mordanting questions? Email [email protected]
YOU ASKED: I realized I purchased aluminum sulfate instead of potassium aluminum sulfate. I am mostly looking to dye cellulose fabric yardage. Will aluminum sulfate work as a mordant for cellulose fibers?
KATHY ANSWERED: Yes, it will work: aluminum sulfate and aluminum potassium sulfate are largely interchangeable. It used to be that aluminum sulfate could contain traces of iron, which would shift colors, but most modern day aluminum sulfate is pretty “clean” – at least I haven’t had an issue with it.
Try our cellulose mordant procedure for the best results, which is the traditional “tannin-alum” mordant you may read about in older dye books. It’s a 2-step procedure with a tannin bath, then an alum bath. Both are room temperature and both baths may be reused. If you don’t have oak gall or gallnut tannin, tara is also very light colored and works great with this mordant process. If you want to use a colored tannin, then myrobalan, chestnut, pomegranate, and quebracho will all impart a yellow tone. Cutch and walnut will impart a fairly dark brown shade. These can create really interesting colors because the tannin influences the dye as well.
Learn more about tannins in our article on 10 Tannins That Don’t Need a Mordant.