Envelope Styles and Sizes
There are plenty of envelope types and sizes available. It's a good idea to choose an envelope that is about 1/4" larger than both the height and the width of the piece you are mailing. This allows for easy insertion but controls possible damage to the enclosure by minimizing excess space.
We have summarized standard envelope sizes for your convenience
Commercial/ Business Envelopes: These are the most popular envelopes for business correspondence, that we send and receive every day. They usually have commercial flap. They are mostly used for letterheads, invoices, statements, checks, writing stationery and direct marketing mailings.
| # |
Size |
| 6-1/4 |
3-1/2" x 6" |
| 6-3/4 |
3-5/8" x 6-1/2" |
| 7-1/2 |
3-3/4" x 7-5/8" |
| 7-3/4 (Monarch) |
3-7/8" x 7-1/2" |
| 8-5/8 (Check) |
3-5/8" x 8-5/8" |
| 9 |
3-7/8" x 8-7/8" |
| 10 |
4-1/8" x 9-1/2" |
| 11 |
4-1/2" x 10-3/8" |
| 12 |
4-3/4" x 11" |
| 14 |
5" x 11-1/2" |
 Invitation/Announcement: The flaps are usually pointed or flat. Mostly used for announcements, invitations, cards, small booklets, brochures or promotional pieces.
| # |
Size |
| A-2 or 2 |
4-3/8" x 5-3/4" |
| A-4 |
4-3/4" x 6-1/2" |
Booklet Envelopes: Also known as “open-sided” envelopes. These envelopes are used for sending catalogs, folder and direct marketing mailings.
| # |
Size |
| 6-1/2 |
6" x 9" |
| 9-1/2 |
9" x 12" |
| 10 |
9-1/2" x 12-5/8" |
| 13 |
10" x 13" |
Catalog Envelopes: Also known as “open-end” envelopes. This style of envelope is mainly used for catalogs, magazines and reports.
| # |
Size |
| 1 |
6" x 9" |
| 1-3/4 |
6-1/2" x 9-1/2" |
| 6 |
7-1/2" x 10-1/2" |
| 10-1/2 |
9" x 12" |
| 12-1/2 |
9-1/2" x 12-1/2" |
| 13-1/2 |
10" x 13" |
| 14-1/2 |
11-1/2" x 14-1/2" |
Window Envelopes: Window envelopes are most often used for bills, though they're also popular for marketing purposes. They are cost-efficient, since the name and address shows through the window, eliminating the need to address the envelope. Normally translucent plastic is used as the window material. Open window envelopes are growing in popularity as more environmentally friendly, however, they are less secure.
Double-Window Envelopes: are often used for checks and invoices. The three probably most popular envelope sizes with double windows are:

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