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.
Jumbo Postcards-oversized postcards can measure up to 6ââ³ x 11Â½,â³ but the postage required is the standard letter rate of 49Â¢. The paper thickness of a postcard over 4Â¼â³ x 6â³ postcard must be at least 0.009â³ and not more than 0.25â³ in thickness.