Leather is a natural material that can be used in different environments and often under aggressive environmental conditions that may cause premature ageing. The most important factors influencing the degradation of leather are temperature, relative humidity and UV radiation. Leathers with chrome tannage and wet-white leathers were exposed to weathering effects using a climatic chamber in order to identify the most important variables affecting this weathering process and to check for interactions. Both a multilevel centralized factorial experimental design and an analysis of variance (ANOVA) have been employed as statistical tools for estimating the effects of the parameters.