The most important thing to remember is that you measure an envelope with the flap at the top!
The height is then always the first measurement and the width the second (Height x Width mm)
Window Size and Position
Again ensure the envelope flap is at the top and measure in the order shown below:
- Measure the depth of the window (A)
- Measure the width of the window (B)
- Now measure the distance from the left hand edge (C)
- Finally measure from the bottom of the window to the bottom of the envelope (D)
Note: The diagram shows an example of a wallet, however the principle remains the same for a pocket (remember to keep the flap at the top) and any orientation of window - landscape or portrait.
The envelope in the diagram could be for instance:
45 x 90 mm, 18 mm Left - 60 mm Up
A x B mm, C mm Left - D mm Up