Postcards
- 4x6, 6x9 and 6x11 postcards: They may be mailed via USPS First Class Mail.
- 6x9 and 6x11 postcards: They may be mailed via USPS Standard Mail, but only within the US.
Self Mailers
- 6x18 and 12x9 bifold self-mailers: They may be mailed via USPS First Class Mail or Standard Mail, but the latter may only be within the US.