Gelatine and glue are two proteinaceous materials much used as media and adhesives by artists and craftsmen. Their fundamental structures and properties are discussed together with some aspects of their degradation. Methods of quality control are touched upon. In the experimental section various types of glue and gelatine are compared on the basis of viscosity measurements and optical rotatory power of their solutions. The results obtained indicate that the problem is complex. Includes tables of analysis of amino acid contents, and viscosity and optical rotatory values in distilled water, 1.98 molar potassium thiocyanate and 0.15 molar potassium acetate buffer solutions. References.