STRAW

STRAW #103 Washfast Acid Dye

These acid dyes are for animal fibre - wool, silk, alpaca, mohair etc. They will also dye nylon. They are very concentrated, so you need only a small amount. 

This is a one-ounce jar of powdered dye.  One ounce will dye six pounds of fibre a medium shade.

All you need is fibre, fabric or yarn, a dye pot, and some vinegar or citric acid.