(formerly "Discharge Paste") deColourant is a ready-to-use printing paste for removing areas of color from dyed natural fabrics such as cotton, linen, silk and wool. Unlike bleach, deColourant removes color without jeopardizing the integrity of the fiber. How does it work? deColourant is activated by heat. If you don’t like what you’ve done, just wash it out! Nothing happens until you heat the deColourant print.