How to Dye Synthetic Fibers
Nylon can be dyed with an acid dye, just like protein fibers (such as wool and cashmere). Polyester can be dyed using a lot of heat. Crayola fabric markers can be rubbed onto paper, then ironed onto polyester. Dip-dying polyester, on the other hand, should only be attempted by professionals or hobbyists that have a lot of experience with dying fabric. Acrylic is difficult to dye and should only by dyed by professionals. Rayon (viscose) is a processed cellulose fiber and can be dyed with fiber reactive dyes, just like natural cellulose fibers. Spandex cannot be dyed at home.
Combined fabrics can make dying more complicated. Nylon/Cotton blends, for example, can be dyed using an all-purpose dye, because these dyes contain both acid dyes (for the nylon) and fiber reactive dyes (for the cotton).
