BOOKS postcard set of 20 postcards. Book, library and reading theme post card variety pack. Made in USA. This set contains 20 postcards, one 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, gifts, invitations, or just sending a note to a friend. Printed in USA.