"Material - OK." Everyone seems to look for a fast reply when asking about the ability of a material to meet the demands of a particular application. In this pushbutton world of computers and keyed-up society one is accustomed to rapid service. The complexity of proper analysis, however, may not permit the immediate response desired. In any evaluation, a comparison must be made between the properties of the material and the properties needed for the application. Realizing the futility of making such evaluations without adequate information on the critical properties of materials, Underwriters Laboratories Inc. has acted as a catalyst in the development of programs leading to the sagacious selection of suitable materials for end-product applications.