Patent ID: 8057884

Claim:
A glass pane that is tempered and then heat-treated, comprising: a marking field that includes an uneven surface structure and that is located on a limited area of a smooth side surface of the glass pane, the limited area being smaller than a total area of the side surface of the glass pane, and the uneven surface structure being more rough than portions of the side surface of the glass pane that are outside of the limited area of the side surface of the glass pane; and a marking layer located on the marking field such that the marking layer penetrates intermediate spaces or hollows within the marking field so as to create an intimate adhesive bond between the marking layer and the marking field, wherein the marking layer includes a color containing a thermochromic pigment that is irreversibly modified at a temperature at which a heat treatment is conducted, so as to visually indicate that the heat treatment has been conducted on the glass pane, and wherein the uneven surface structure of the marking field is discontinuous such that bare portions of the side surface of the glass pane are exposed to the marking layer.