Flip on short edge vs long edge: which duplex setting for a booklet or zine

When a printer prints on both sides it has to turn the sheet over, and there are two ways to do that. Flip on long edge turns the sheet like a page in a portrait book: the long side stays put and the sheet rotates around it. Flip on short edge turns it like a page on a flip chart or a landscape calendar: the short side stays put. Pick the wrong one and the back side comes out upside down relative to the front.

The names describe the axis the sheet rotates around. Long-edge binding means the two sides share a long edge as their common top-to-bottom orientation; short-edge binding means they share a short edge. Some drivers call them “book” and “tablet”, or “long-edge binding” and “short-edge binding”, but it is the same pair of options.

The common rule is “portrait document, long edge; landscape document, short edge”. A booklet sheet is landscape, with two portrait pages side by side and the fold running down the middle, so booklet guides tell you to flip on the short edge. That is correct for a landscape PDF sent to a driver that sees it as landscape.

The confusion comes from tools that pre-rotate the page. Some booklet imposers output a portrait page with the two book pages rotated sideways, and for that file the right setting is long edge. Both are the same physical movement: the sheet turns about the axis parallel to the fold line. The setting is relative to how the driver sees the page, not to how you see the finished book, which is why two accurate guides can give opposite advice.

Do not try to reason it out; test it. Print one sheet of the booklet on both sides, then hold it up to a window or lamp. The page printed on the back should be the right way up behind the page on the front, sharing the same top edge. If it is upside down, reprint that sheet with the other setting and you are done. It takes ten seconds and one sheet of paper.

Foldpic's test page is designed for exactly this. It prints a large letter A in one corner of the front and a B on the back so that when the flip is right the two letters sit on top of each other, and cross-hairs in two corners on both sides so you can see any horizontal or vertical offset at the same time.

If you would rather not deal with duplex at all, choose a format that only prints on one side. The 8-page one-sheet zine is printed single-sided and folded so the blank back disappears inside. The accordion album is also single-sided, which means it can be printed on glossy inkjet photo paper that is only coated on one face. Both formats have no front-to-back registration to worry about, which is why they are the best choice for photo-heavy projects on a home printer.

The stapled booklet is worth the duplex step when you want a real book with 16 or more pages. Once the flip setting is confirmed for your printer it stays the same for every booklet you print.