![USPS Priority Express Flat Rate Envelope USA Shipping Address Only Item Purchased From the Antique Appeal Only - Etsy UK USPS Priority Express Flat Rate Envelope USA Shipping Address Only Item Purchased From the Antique Appeal Only - Etsy UK](https://i.etsystatic.com/11300852/r/il/d38e74/2490944454/il_fullxfull.2490944454_rbg9.jpg)
USPS Priority Express Flat Rate Envelope USA Shipping Address Only Item Purchased From the Antique Appeal Only - Etsy UK
![USPS Mailing Guidelines for First Class Mail - Letters, Postcards, Envelopes & Packages - MITO Studios USPS Mailing Guidelines for First Class Mail - Letters, Postcards, Envelopes & Packages - MITO Studios](https://www.mitostudios.com/wp-content/uploads/2012/01/usps_phx_domestic_letters.jpg)
USPS Mailing Guidelines for First Class Mail - Letters, Postcards, Envelopes & Packages - MITO Studios
![USPS First Class Template Size Guide Ruler Measuring Tool Postal Slot Gauge Large Envelope Shipping Tool - Etsy UK USPS First Class Template Size Guide Ruler Measuring Tool Postal Slot Gauge Large Envelope Shipping Tool - Etsy UK](https://i.etsystatic.com/34059611/r/il/51c54d/3661838555/il_fullxfull.3661838555_td1z.jpg)
USPS First Class Template Size Guide Ruler Measuring Tool Postal Slot Gauge Large Envelope Shipping Tool - Etsy UK
![USPS Mailing Guidelines for First Class Mail - Letters, Postcards, Envelopes & Packages - MITO Studios USPS Mailing Guidelines for First Class Mail - Letters, Postcards, Envelopes & Packages - MITO Studios](https://www.mitostudios.com/wp-content/uploads/2012/01/usps_phx_domestic_lrg_env.jpg)