The following figure shows the relationship between the optical print density and the energy supplied by a thermal head.

The following figure demonstrates the erasing property of ThermoRewrite.
A hot iron stamp is used to estimate the erasing temperature for ThermoRewrite. The figure indicates how the optical density decreases with the increase in temperature of the hot iron stamp. In this case, the erasing temperature was estimated to be about 120^oC (conditions: contact time 1.0 s, pressure 1.0 kgf/cm², 9.8x10^-2MPa)