Priority Mail Flat-Rate Envelope
Envelope size: 9-1/2 X 12-1/2 inches.
Regardless of the weight or destination for items mailed in the Priority Mail flat-rate envelope provided by the Postal Service, the price is $4.80 at Retail or $4.75 through Click-N-Ship at USPS.com.When sealing a flat-rate envelope, the container flaps must be able to close within the normal folds. Tape may be applied to the flaps and seams to reinforce the container; provided the design of the container is not enlarged by opening the sides and the container is not reconstructed in any way.
