Alum is an easy way to pretreat your textiles to create stronger color bonds with natural dyes. The 'mordant' process is an extra, but important, step to help organic color last longer and protect it from fading with exposure to light and wash. Typically found in your grocery spice aisle, alum is a mineral most often used by natural dyers on its own or in combination with other mordants such as tannin. The process is as easy as simmering a pot of a water and soaking your textile for an hour. This video tutorial will show you how to make an alum bath, as well as the use of cream of tartar for protein fibers.