As required by local building codes, a 5/8”W x 1/8”H permanent stamp is placed on all sections of our glass to signify that it has been tempered. If a particular door style has multiple panes, all of the sections will be stamped. In an effort to make the required stamp as inconspicuous as possible, the stamp is placed on the lower right hand corner of each pane, and the letters are colored in white. With insulated glass, the stamp is only placed on one side of the sandwitched section. With Beveled or Sand Blast insulated, or architectural insulated glass over clear, the stamp is always placed on the interior, clear side.