Saxon Blue liquid extract is best for dyeing protein fibers, such as wool and silk. It is not recommended for dyeing cellulose fibers, as it is not as lightfast on plant fibers and it is acidic and cellulose fibers do not handle acids as well as protein fibers.
Saxon Blue was created in the 1740s in Germany soon after the discovery of sulfuric acid. The combination of powdered indigo with sulfuric acid, and a bit of chalk, makes an easy to use liquid indigo dye that can be used as a direct dye, applied in an immersion bath with or without the use of a mordant. The use of a mordant such as alum, may improve its lightfastness, and I have seen sites confidently saying that a mordant must be used when dyeing with it, but I am fairly confident in saying that is not true.
Saxon Blue is satisfactorily light fast on protein fibers. To use, simply fill a non-food use pot with hot water, add a little bit of the Saxon blue liquid and give a stir. It is best to pre-soak the fiber that you are going to dye, in hot water, as this will help the fiber dye more evenly. Heat the pot on the stove, to a simmer, and if the color is not as dark as you’d like, pull the fiber out of the pot, add more liquid dye, give it a stir, and re-enter the wet fiber.
You can simmer for as long as you’d like, and let the fiber cool down in the pot, or take it out when you are pleased with the color. Rinse out your fiber, and and you can use a ph neutral detergent like original blue Dawn if you’d like to use a bit of soap when you rinse.
Saxon Blue is made with powdered natural indigo, but dyes a decidedly more turquoise or greenish blue color than when using an Indigo dye vat to dye fibers.
Saxon Blue makes dyeing with Indigo, for a range of blue hues, so much quicker, and easier. You can over-dye easily with Saxon Blue for a whole range of purples, and the most amazing bright greens and teals.