100% Dye-Lishus® cotton sliver. Before it was carded, the cotton was treated with an industrial strength mordant so that it attracts and holds dye withou the need for any other chemicals. You can use acid, direct, fiber reactive and natural dyes. If you dye wool and have acid dyes, you do not need to buy any other dyes. It has a pink fugitive tint to mark it as different from untreated cotton. It will wash out in hot water.