Postcard
Use for cards with the following dimensions:
Dimension Minimum Maximum
Height 3-1/2 inches 4-1/4 inches
Length 5 inches 6 inches
Thickness 0.007 inch 0.016 inch
Any item smaller than the minimum dimensions is not mailable.
For postcards, length is the dimension parallel to the address.
Postcards must be rectangular and be made of unfolded and uncreased paper or card stock.