Free Padded Flat Rate Priority Envelopes
The reason most people don't know about them is because they're not available at the post office and can only be obtained through the USPS.com/shop website.
The 9 ½ by 12 ½ inche envelope is for domestic shipping only and come in packages of 5, 10 or 15 envelopes.
As with other flat rate envelopes, “if it fits, it ships” anywhere in the country for $4.95. As an added bonus, shipping labels printed with click-n-ship from usps.com receive free delivery confirmation service.
To order these and some other items that are not available at your local post office, click here.