How To Place Content In Letters
When designing your document, make sure you follow these guidelines.
Address (Bottom) Window
To make sure the recipient address will fully appear through the bottom window, however the paper may shift inside the envelope (see explanation below), make sure it is placed in a rectangle which top-left corner is placed 0.5” from the left paper margin and 2.042” from the top paper margin. The size of the rectangle must not exceed height 0.875” or width 3.5”.
Return Address (Top) Window
To make sure the return address will fully appear through the top window, however the paper may shift inside the envelope (see explanation below), make sure it is placed in a rectangle which top-left corner is placed 0.5” from the left paper margin and 0.5” from the top paper margin. The size of the rectangle must not exceed height 0.792” or width 3.5”.
The following image shows the measurements of correctly-placed address blocks in a document. These measurements assume the letter is located at the bottom-left part of the envelope. In case the letter shifts upwards or sideways, the postal agency machinery and the postal delivery worker will still be able to read the address.
Content should be limited to 0.5 inch margins on the top, left and bottom and to 0.6 inch on the right. Anything outside these margins might not be printed.
It is best to start writing the body of the letter 3 3/8" from the top of the page and 0.5" from the left.
Bar Codes and LetterIDs
Two types of identification marks are printed by PostalMethods. Address marks (marked as E and F in the picture below) are printed on the first page of the letter only. Page marks (marked as G and H in the picture below) are printed on every sheet of paper (which means only on odd pages in duplex printing). These marks are required for document fulfillment and customer support.
Reserved areas on a letter size (8.5"x11") paper
Why are there limitations at all?
Number 10 envelopes are 4.125” high and 9.5” wide. Letter size paper is 11” high and 8.5” wide. A letter size folded in three is 11”/3 = 3.667” high. According to these measurements, a letter size paper, folded in three, inserted into a number 10 envelope - may shift inside this bigger envelope. There is a full inch (9.5” – 8.5”) possible horizontal movement and 0.458” (4.125” minus 3.667”) possible vertical movement.
Furthermore, postal agencies require that the recipient address appear in full through the bottom window and that there would be a margin of at least 0.125” between the address and the window borders.