Protection against phototendering of wool by metal salts and mordanted dyes

Samples of treated and dyed wool have been irradiated with an artificial UV radiation source with a spectral distribution that matched the summer solar UV spectrum. The extent of phototendering was determined by measuring the loss of tensile strength of strips of wool fabric. Many of the dyes studied accelerated phototendering, although some metal-complex dyes prolonged the lifetime. Significant protection of wool against phototendering could be obtained by treatment with aluminium salts, or related salts, followed by dyeing with classical mordant dyes.