Degradation of printing elements under the influence of light and wetting solution

Before the printing proces, on the offset printing plate a degradation of unprotected printing elements under daylightcan occur. On such degradated printing elements that changed their chemical composition, the wetting solvent added to the printing form before zhe printing process, influences too. In this work spectrophotometric properties of a positive acting diazo printing layer exposed to daylight were performed. As well spectrophotometric properties of such layers after chemical treatment in various wetting solvents were examined.