We think the easiest course of identification is as follows
1. Determine which of the five designs the stamp has (see below).
2. Determine the denomination of the stamp, which entails simply reading the number on the stamp.
3. Determine the perforation of the stamp in the top or bottom margin.*
4. Determine the perforation of the stamp in the left or right margin.*
5. Determine the printing process: flat plate, rotary press, or offset using the helpful tips provided.
6. Determine the type of watermark if necessary.
7. Determine the type: 2¢ Types I-III · 2¢ Types IV-VII · 3¢ Types I and II · 3¢ Types III and IV
Most of the Washington Franklin Heads may be identified using only three or four of the above steps.
*For compound perforations, stamps with more than one gauge of perforations, the convention is to list the gauge of the horizontal perforations first and the vertical perforations second. For example, Number 423A perf 12 x 10, is perf 12 top and bottom and perf 10 along the sides, while Number 423D perf 10 x 12, is perf 10 top and bottom and perf 12 at the sides.