Envelope 101

It is highly unlikely that a person goes throughout their entire day without handling an envelope of some sort. We all know what an envelope is and what one looks like, however many may not know the name of that particular envelope, the sizes, what size piece will fit within, or what other options are available to choose from.

For the next time you need to send an invite, thank you card, letter, or a packet of information, be sure to consider the below when purchasing the envelopes you need. There are more options than you would even imagine!





4 3/8” x 5 3/4”

4 1/4” x 5 1/2”


4 3/4” x  6 1/2”

4 1/2” x 6 1/4”


5 1/8” x 7 1/8”

5” x 7”


5 1/2″ x 8 1/8”

5 3/8” x 7 7/8”


5 3/4” x 8 3/4”

5 5/8” x 8 5/8”


6” x 9 1/2”

5 7/8” x 9 3/8”


3 7/8” x 8 7/8”

3 3/4″ x 8 3/4″

#9 Policy

4” x 9”

3 7/8” x 8 7/8”


4 1/8” x 9 1/2”

4” x 9 3/8”


4 1/2” x 10 3/8”

4 3/8” x 10 1/4”

#9 ½ Booklet

9” x 12”

8 3/4” x 11 3/4”

#13 Booklet

10” x 13”

9 3/4” x 12 3/4”

#10 ½ Catalog

9” x 12”

8 3/4” x 11 3/4”

#13 ½ Catalog

10” x 13”

9 3/4” x 12 3/4”

*please note that this list is not inclusive of every envelope size. These envelope sizes are commonly used and typically readily available.


Announcement style envelopes are commonly used when sending photographs, greeting cards, promotional pieces, informal mailings and both social and commercial announcements. Baronial style envelopes are traditionally used for formal announcements and invitations. These envelopes are not recommended for machine insertion. Announcement and Baronial envelopes represent the A size envelopes in the above chart. These envelopes can be printed on either laser printers or on a press.


Business style envelopes are your standard everyday business, or personal, correspondence  envelopes.  These commercial or side seam business envelopes are well suited for inserting contents by machine.  The business envelopes are also available in wallet flaps or square flaps which are not recommend for machine insertion. Business envelopes can be printed on using a laser printer or can be printed on a press. The most common of this style envelope is the #10 size, often seen with or without windows. Business style envelopes represent the #9, #9 policy, #10,  and #11 envelopes in the above chart.


Booklet style envelopes are great for annual reports, large brochures, and various sales materials. These envelopes open on the long dimension and cannot be processed through inserting equipment. In addition, these envelopes cannot run through a laser printer and must be run on a printing press. In order to protect the contents, this style envelope typically has a heavily gummed flap to seal. Booklet style envelopes represent the #9 1/2 and #13 booklet envelopes listed in the above chart.


Catalog style envelopes are similar to Booklet style, the main difference being that they open on the short dimension rather than the long dimension. These envelopes too have heavily gummed flaps for sealing. This style envelope is great for sending catalogs, books, manuals or packets of documents. Catalog envelopes are unable to be processed through inserting equipment and are unable to be run through a laser printer. Catalog style envelopes represent the #10 1/2 and #13 1/2 catalog envelopes listed in the above chart.


All of the envelopes mentioned above are available in a wide variety of colors, textures, and finishes. We would be here all day listing every envelope out there – the options are limitless. Call you local Avalon today if you have questions on envelopes, or need to have envelopes printed!

If you liked this blog you might also be interested in reading: Your Pocket and the Post Office

Learn how Avalon’s secure print and mail services allow you to focus on the bigger picture.

Case Study: Secure Printing & Mailing 

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Ian Gattie