Two of the most popular dyeing techniques in Africa are tie and dye and resist dye. In tie and dye, designs are first tied or stitched into the cloth, using cotton or raffia threads. In resist dye, dyers draw on the cloth using an impermeable substance, such as candle wax or paste made from cassava, a tuber. They then dip the fabrics into solutions typically made from vegetable dyes, which colour all but the covered areas. Indigo plants are used for deep blue dyes.