4. Pair of full stamps with the interpane gutter between: The great majority of U.S. stamps have been issued to the public in panes of 50 or 100, but they were printed in larger formats and then cut into panes. If cut incorrectly for any of several reasons, they command prices in the $100 range and up.
Type 4: Foldover with miscut results in a pair with full gutter between (Scott 1584).