Alum is a mordant for natural dyeing that creates bright, cheery, colourfast tones. Most natural dyes need to be used along with a mordant in order to help the colour attach to the fibre, and alum is the most commonly used.
Available in 50g or 100g recycled paper envelops.
Use alum at 8-15% of the dry weight of fibre (WOF). (Eg. For 100g of fibre, use 8-15g alum.)
In the samples in the last image, the bottom row was mordanted with alum, while the top row was mordanted with iron (another mordant used to darken colours). Each column is dyed with the same plant; from left to right, marigold, cochineal, and madder root.
Equipment and Saftey
Pre mix each dye vat ingredient in small containers of water to avoid lumps. Always add powder to liquid, not liquid to powder (to prevent powder from flying everywhere). Wear gloves and an apron to prevent staining your hands or clothes. Always dye in a well ventilated area and use separate pots and utensils from your cooking pots.