Abstract
Abstract Researchers are constantly looking for the use of new and effective types of natural dyes to reduce the impact of harmful factors from the use of synthetic dyes. In this study, the effects of a natural plant extract based on oak bark, used as a dye during the finishing process, on the physico-mechanical and hygroscopic properties of the leather were studied. Extraction was carried out by the traditional method without chemical additives using only distilled water and oak bark. The application of finishing solutions based on a standard chemical pigment and oak bark extract was carried out using an automatic rotary spray machine in combination with a drying tunnel. The physico-mechanical properties of colored leathers based on oak bark extract were determined in comparison with a standard chemical pigment and with a sample without finishing. The hygroscopicity of the leather samples were also evaluated, such as: water absorption, water penetration and color fastness to water spotting. The results of the conducted studies have shown that the samples stained with a natural dye have good physico-mechanical and water resistance properties.