what is half of 8 1/2 x 11 paper
Letter (paper size) The related paper size known as half letter, statement, or organizer L is exactly one half of the US Letter size: 8.5 by 5.5 inches (220 by 140 mm) (8.5 × 5.5 in).
Duplex printing Duplexed documents can be printed to be bound on either the short edge or the long edge. This functionality is mostly available on printers that come with a duplexer.[1] Long edge binding in portrait mode allows pages to be turned side-to-side like a book. Short-edge binding allows the pages to be oriented correctly if they are flipped vertically, as in a notepad. This second form of printing/binding is sometimes known as "tumble." If the printing is done in landscape mode, these concepts are transposed since the print direction is different.