Apply a line of dye along fabric edge. Use a large wet paintbrush to push dye upward on fabric. Continue dipping brush into water and brush along edge of dye, pulling colour upward to create a gradation of the original colour.
fabric printing with bleach/Dyeing fabric with bleach. Applying ordinary household bleach to dark, natural-fiber fabrics, either by spraying or brushing the bleach on flat fabric (Resist-and-spray technique), or by dipping the fabric in it, after protecting part of the surface in some way from contact with the bleach. http://www.threadsmagazine.com/item/3720/dyeing-with-bleach