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.
Choose from common greeting card sizes. Generally, you will base the size of your cards on popular envelope sizes. This will not only make them easier to package and sell, but they will also to tend to fit better into standard card rack sizes, which makes them easier to merchandise in stores or at craft fairs. Typical greeting card sizes include 4.25 by 5.5 inches, 4 by 6 inches, and 5 by 7 inches. If you're working with a printer, be sure that the cards come with envelopes. Note: Many find that the card size measuring 4.25 by 5.5 inches is a great format with which to begin your greeting card adventure.