A practical and economical system of casting testers, formed by simple constituents that can be found anywhere, has been developed. Pattern formation is a quick procedure, and because the testers are small and imitate forms familiar to dental technicians, they can incorporate them easily into their daily work routine. Results can be interpreted without the use of any apparatus, because they are based on the principle of all or nothing. The proposed sytem was field tested in 13 commerical dental laboratories, and the percentage of successes obtained affirmed that the goals of the procedure are attainable and valid.