Over 95% of grills are either E or F grills. The A, B, C, and D grills had proved to be unsatisfactory, mostly due to their presence on the stamp making the stamp difficult to separate. The Z grill did not have that problem but for whatever reason it was printed in very limited quantities. The E grill is often confused with the Z grill as the size of the grill is similar and they are on the same values. Close examination of the E grill will reveal the grills has a vertical orientation as shown above. Whilst the Z grill has a horizontal orientation. Both the E and Z grills have their grill points facing down (see types of grills).

This stamp is often found on very thin paper, which made a more defined grill than ordinary stamp paper.