The Instanta Perforation Gauge is a vital piece of equipment, measuring perforations on stamps to one decimal point.

The perforation gauge measures the number of perforations within the measure of 2 centimetres. Perforations are a stamps teeth and their measurements vary according to the type of perforating machine used.

Often the stamps top and bottom perfs differ from those at the sides (called a compound perforation), and measurements range from 7 (large holes) to about 18 (small holes)