Enhanced UV blocking is provided to clothing by washing the clothing in a composition including a UV blocking dye and at least one additional water-soluble material which serves as a matrix and/or a dispersant for the dye in the washing machine. The dye is initially in the form of a solid tablet or pellet preferably also containing a disintegrant, or inside a water-soluble envelope. When placed in the washing machine with the clothing and the washing water, the pellet or tablet disintegrates and dissolves releasing the UV protectant dye to the clothing.