Seven Strategies to Navigate USPS Regulations for Effective Self-Mailers (piworld.com)

As you know from our post on postcards, there are many times that a design element causes a mailing to go at a higher rate of postage. This can be frustrating as well as expensive. In order to help you stay away from potential issues here are some things to keep in mind as you are preparing a direct mail campaign.

Now let’s look at Self-Mailers:

1. Self-Mailer size is 5 x 5 to 6 x 10.5, anything larger is not mailable in this category.
2. Paper stock must be a minimum of 70lb, as long as the weight is under an ounce.
3. Keep your aspect ratio between 1.3 and 2.5.
4. There are two options for addressing a self-mailer. Barcode in the address block: 4 x 2 clear area, no varnish, UV coating, text, or images for the address block.
5. There are two kinds of folds horizontal and vertical: For horizontal folds: the final fold is below the mail panel.
6. Tabbing or fugitive glue closures are required: If tabbing: up to 1 ounce mailer needs two 1 inch tabs, mailers over 1 ounce need two 1.5 inch tabs and if you are using perforations or inserts it needs two 2 inch tabs.
7. Poly bag/envelope: If you use a poly bag or envelope your mail will have to go at flat postage rates.
   details at: https://www.piworld.com/post/seven-strategies-to-navigate-usps-regulations-for-effective-self-mailers/