Few of the resins used to conserve objects were developed specifically for that purpose. For that reason, the British Museum has a policy of assessing all materials prior to their use with objects. Procedures for determining the tensile properties of resin films and adhesive bonds were defined in the early 1980s, but it is now felt that a more extensive repertoire of mechanical tests is necessary with the increase in the range of available formulations and conservation techniques. This paper describes the development of the standard tests for testing materials currently used by the Conservation Research Section of the British Museum, their applications and limitations. -- CAL