SolarFast Wash removes the undeveloped dye from fabric and paper and reduces the risk of back staining during washing. This is especially important for preserving white areas and highlights when making photographic prints. For machine washing use 3-4 capfuls (24ml) per load. Set washer to hot for best results. For front loading machines with a pre-wash flush, add SolarFast Wash after pre-wash and before wash cycle. For hand washing fabric or paper, submerge in hottest tap water possible, add 1-2 capfuls (10ml) SolarFast Wash, agitate constantly and keep water flowing for 10 minutes.