Type A: P13.5
Type B: P13.5 but P14 at top
All the four spider stamps have these two types of perforation. The spider stamps were printed in sheetlet of 20. The layout of stamps in a sheetlet is shown in the image below. The type B perforation located at two sections in the sheetlets for all the denominations - upper top pane (row 1) and the bottom pane (row 4) of the sheetlet. This means that 50% of stamps are of type A and the other 50% is of type B.
