Dye will flow on wet fabric, the way watercolor paint spreads on wet paper.  Attempting to guide, cajole, restrict, tempt, and encourage the dye to go the way I wish is endlessly challenging and fascinating.  Many people imagine that when I dye fabric, I begin with black fabric and “take away color” with bleaching techniques. It is actually the opposite - my original ground color is always white, and I add color and black in as I go.