A system for regulating heating temperature of a material is provided. a tensile modulus of at least 2600 MPa,II. The one signal processing unit processes one or more electric signals output from the one or more encoder heads. A shape of the progressive-power surface of the spectacle lens is different from a shape of a progressive-power surface of a reference lens that is defined as a lens identical to the spectacle lens except that the prescribed prismatic effect is eliminated. In one embodiment, the ink or graphics layer is positioned between said heat-activatable adhesive layer and said facestock.