US NATIONAL PARKS postcard set of 20. Post card variety pack depicting American national parks postcards. Made in USA. This set contains 20 postcards, 1 of each design. Size 4 x 6 inches (10 x 15 cm). Glossy UV coating on front for durability and protection. Our postcards are printed on 16 pt (360 gsm) premium sturdy quality cardstock. This is the maximum thickness allowed by USPS for a postcard to be mailed without an envelope. Ideal for collectors, Postcrossing, scrapbooking, school postcard exchange projects, invitations, or just sending a note to a friend. Printed in USA.