1963-66 Blue, Mr. Zip with Press-Printed "DUMMY"

Test booklets were used by the US Postal Service to experiment with new stamp designs, printing methods, and materials before releasing stamps to the public. They helped assess features like perforations, gum, and security measures. These booklets are scarce and collectible today due to their historical significance.

This test booklet features Mr. Zip on the cover and overprinted “DUMMY” in red. Inside, you’ll find four panes, each with six “test stamps” on them. The panes are blank white, with gum on the back and perforated. Plus, behind each pane, there’s interleaving to keep everything in perfect condition. It’s a fascinating piece for any collection!