Abstract

The quality of finished leather is often determined based on the grain characteristics or pattern. The grain characteristics of leathers vary according to the age of the animal, breed, gender, climate, animal husbandry practices and processing conditions. However, the assessment of the leather surface or grain characteristics is often subjective. In this study, the grain characteristics were determined using a profilometry technique. Profilometry, a metrological method, is essentially the measurement or assessment of surface texture which is interrelated with its friction and wear properties.

The aim of the study was to define and grade the leather surface based on a given scale as well as to analyse the effect of various leather-making operations, including tanning, on the grain texture of leather from species of different origins.

Hides (bovine) and skins (caprine) were subjected to various processing conditions, including deliberately extreme conditions, such as extended liming processes and a shrunken grain tannage. The topography of the grain surface was analysed using an optical profilometer; with the 3-dimensional stitched scans produced verified by scanning electron microscopy.

The results demonstrate a technique that could be used in forensic, quality control and research contexts to provide tanners with an indication of the impact of their processing on the grain pattern of their leather.