Applicability of the New Rules. The new cargo securement rules apply to the same types of vehicles and cargo as the old rules, covering all cargo-carrying commercial motor vehicles (as defined in 49 CFR 390.5) operated in interstate commerce.
Most commercially-produced postcards measure approximately 4.21 inches by 5.47 inches. Less commonly, smaller postcards are typically 3.5 inches by 5.5 inches, close to the minimum size the USPS allows.
Specifically this is for: a card having dimensions between: 3 1/2 x 5 x .007 thick. 4 1/4 x 6 x .016 thick. To send a postcard to an international destination the rate is $1.20, up from $1.15 as of the same May `015 date. As of Jan `014 large postcards rose 3 cents to $0.49, up from $0.46 to mail. These have maximum dimensions of 11 1/2 x 6 1/8 and can measure up to 1/4 thick.