A series of twenty controlled experiments was undertaken to determine whether heat treatment alters the speed, intensity, or appearance of wear on the edges of flint tools. Four hypotheses were tested with the following results: heat-treated tools wore more quickly and with more severity than tools which had not been heated. When used in the same fashion and on the same materials, heat-treated flakes showed longer microflake removals from use than did non-heat-treated flakes. The use of these flint tools yielded more step and hinge flake terminations on the heat-treated tools than on the non-heat-treated tools. Flake scars from microflaking due to use had a shiny surface on flints which had been heat-treated, while such surfaces were matt on unheated materials. The results suggest that these effects should be taken into consideration when studies of use-wear are undertaken. See also AATA 20-2096. -- AATA