OKLAHOMA STATE FACTS postcard set of 20 identical postcards. Post cards with OK facts and state symbols. Made in USA. This set contains 20 identical postcards. 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, gifts, invitations, or just sending a note to a friend. Will mail with USPS postcard rate stamp domestically, or with international forever stamp if mailed overseas. Printed in USA.