Size of a Window Envelope
Window envelopes are available with these window sizes:
- The standard window is 1-1/8 inches high and 4-1/2 inches wide, and is placed 5/8 inch from the bottom edge of the envelope.
- In size 6-3/4 envelopes, the window is 7/8 inch from the left edge.
- In size 10 envelopes, the window is 1 - 1/16 inch from the left edge.
- On double window envelopes, the second window (designed for return information) is 1/2 inch from the top and left edges, and measures 3/4 inch high and 2-1/2 inches wide.
Other window sizes and locations can be produced, if the window is:
- Not more than 1-1/2 inches high.
- Not more than 5 inches wide.
- At least 1/2 inch from the bottom edge of the envelope.
- At least 3/8 inch from any envelope edge.
Window Cover Material
- Window cover material:
- Must be made of a nontinted clear or transparent material (e.g., cellophane or polystyrene).
- Must permit information, as viewed through the window material, to meet the print-contrast ratio standards to ensure efficient processing.
- Glassine may be used for window cover material.
- All edges of the window cover material must be glued securely to the envelope.
In general, windowed envelopes must allow compliance with general United States Postal Service® guidelines.
If you have any questions about valid envelope window sizes, refer to the Mailing Requirements area of your local Post Office™ facility.
Inserts or Mailpieces Going Into Window Envelopes
Mailers using window envelopes (both letter-size and flat-size) should design inserts and address element placement to ensure successful processing of window envelopes on automated equipment. One critical element that must be considered in the design stage is adequate clear space (blank space) between the address block and all four edges of the window. The mailpiece should be designed so that when it is inserted into the window envelope the address block will appear in the window no matter how it is shifted or moved within the envelope.
What are the Clear Space Requirements for a Windows Envelopes’ Address Block?
The requirements for clear space around the address block are as follows:
- For non-automation mail - except letter-size mail bearing a barcode in the address block and submitted at Enhanced Carrier Route high density and saturation prices - a clear space of at least 1/8 inch is required between the address block elements and the top, bottom, left and right edges of the window.
- For automation mail and letter size mail submitted at Enhanced Carrier Route high density and saturation prices bearing a barcode in the address block:
- A clear space of 1/8 inch is required between the address block (including barcode) and the left and right edges of the window.
- A clear space of 1/25 inch is re