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Envelope Fundamentals – Learning the Basics!

Michele Rosenberger Michele Rosenberger Senior Sourcing Manager

PS sat down with Michele Rosenberger, Senior Sourcing Manager, to get the low-down on envelopes and all that you need to know about them for a successful campaign. Check out this quick but informative Q&A with Michele, a Resource/Production Expert:

PS: Are there standard sized envelopes and is there an advantage to using one instead of a custom size?

MR: There are some standard sizes for envelopes such as #10, #9, 9 x 12, 6 x 9. If using these types of envelopes, they can be more easily accessible and require less turn time from printing to delivery. Typically, a standard envelope can get you a better price-point than a non-standard size, so time and cost will be an advantage.

PS: What is the largest size envelope I can mail with just a single 1st class stamp?

MR: The maximum size/measurements that the USPS allows to mail at letter rates (single 1st class stamp) is 11 ½ inch length and 6 1/8 inch height.

For a standard letter size envelope we would say a #14 (5 x 11 ½) would be your max length and a 6 x 9 would get you a max height.

PS: What is the smallest size I can mail?

MR: The minimum size/measurements that the USPS allows to mail at letter rates is a 5 inch length and a 3 ½ inch height.

For a standard envelope size, it would be a A2 (4 3/8 x 5 ¾) for length and #6 ¼ (3 ½ x 6) or #6 ½ (3 ½ x 6 ¼) for height.

PS: Are there rules around where the envelope window is?  Can I place it anywhere?

MR: The main rule for windows is that you need at least a minimum of ½” from the side and bottom to ensure acceptable room for the window patch to be attached to the envelope. Windows can come in all shapes and sizes, and can be placed on the front and/or back of the envelope. You can even do a custom window design/shape or multiple windows.

Be sure to check out our standard Envelope Size Chart here, to learn more:


If you have any questions about our Envelope Size chart, or about envelopes in general, don’t hesitate to reach out to your PS contact!

About the Author

Michele Rosenberger
Michele Rosenberger Senior Sourcing Manager

Michele is a Senior Sourcing Manager and has been serving with PS since 2007. Working full-time from Myrtle Beach, South Carolina, Michele enjoys playing with her beagle and her kids, and she also enjoys playing volleyball. 

Michele has made an extraordinary impact with her clients and their missions by staying positive and practicing excellent customer service. Michele has had the pleasure to serve, HFH, NMAI, EDF, SOI, NPF and currently works with Easter Seals.