Whitening

Noun

 * 1) a substance, such as a bleach, used to make something white or whiter
 * 2) the process of making something white or whiter

Thesaurus
achromatization, albification, blanching, bleach, bleaching, calcimine, decoloration, decolorization, decolorizing, discoloration, etiolation, fading, frosting, grizzling, lightening, madder bleach, market bleach, paling, pipe clay, silvering, whitewash, whitewashing, whiting