In the Trade Mark the words TRIPLEX and TOUGHENED were arranged in a circular formation around a triangular arrangement of the three X’s. Glasses were defined by the quarter of the year (Jan-Mar., Apr-June etc..) and the year of manufacture. The quarters were indicated by a dot above the word TRIPLEX. The year was indicated by a dot under one of the letters of the word TOUGHENED (thus a dot under U would have indicated 1933). For 1940 the dot would be placed to the right of the letter D.
The Trade Mark is made up of the triangular arrangement of the three X’s surrounded by a broken circle, surmounted by the word TRIPLEX. The word ‘Laminated’ does not appear. The quarterly identification is the same as for toughened glass. The years 1930 and 1939 can be identified by the 0 to 9 beneath the circle diametrically opposing the letter P in the word TRIPLEX.