"The simplest way to make indigo yarn and fabrics is to soak fibers in chemical dye. But Aboubakar Fofana, 46, a Malian-born artist and designer, recoils at the thought of a technique that is so undemanding. Indigo leaves for his dyeing vats have been ground with mortar and pestle, and the helpful bacteria that form there are fed often and sometimes given the chance to rest. The result is a shimmering blue that holds up even when left in the sun."