Abstract: A heated vacuum mounting press comprising an upper part which is movable between open and closed conditions, a lower part, a flexible diaphragm, an electrically conductive glass sheet member for being heated by an electric current in order to heat sheet workpiece material in the press, and an air evacuating pump for evacuating air from between the upper part and the lower part of the press when the upper part is in its closed condition on the lower part, whereby the diaphragm is able to be flexed against the sheet workpiece material to provide substantially even pressure over the surface of the sheet workpiece material while heat is applied to the sheet workpiece material from the electrically conductive glass sheet member.