Print a booklet: letter or A4 sheets folded in half, with pages in the right order

Count your pages: always in multiples of 4

Each folded Letter sheet gives you 4 half-letter pages. That's why a booklet has 4, 8, 12, 16… pages. If your document has 10, Word fills it up to 12 with blank pages at the end. Better to decide yourself what goes there: a back cover, a notes page or contact details.

Open “Custom Margins”

Go to Layout › Page Setup › Margins (in Word 2013: Page Layout) and, at the bottom of the list, choose Custom Margins…. The Page Setup window opens, with the Margins, Paper and Layout tabs.

Under “Multiple pages”, choose “Book fold”

On the Margins tab, near the bottom, open Multiple pages and choose Book fold. The orientation switches to Landscape on its own: that's the physical sheet. On screen you'll see portrait pages at half size, which are the faces of the booklet.

Notice that the left and right margins are now called Inside and Outside: the inside is the fold.

Set “Sheets per booklet” and the gutter

With Sheets per booklet set to All, Word makes a single booklet: perfect for up to about 10 stapled sheets. For long documents, choose 4 or 8: Word creates several booklets that you stack and bind together, so the spine doesn't spring open.

Increase the Gutter a little (for example, 0.2") to reserve room at the fold. Check that Apply to says Whole document.

Keep the paper at Letter on the “Paper” tab

On the Paper tab, Paper size is the sheet you'll load into the printer: Letter. Don't pick a half-letter size: the finished booklet is half the sheet, so Letter already gives you 5.5 × 8.5 in pages. Click OK.

Check the layout and number the pages

Scroll through the document: headings that used to fit on one line may wrap, and large pictures may jump to the next page. Shrink whatever needs it. Then add numbers with Insert › Header & Footer › Page Number. You write and number in reading order (1, 2, 3…); Word handles the reordering when it prints.

Print two-sided, flipping on the short edge

Go to File › Print. In the list that says Print One Sided by default, choose Print on Both Sides with Flip pages on short edge. Because the sheet is landscape, flipping on the long edge prints the back upside down.

Printer can't do two-sided on its own? Choose Manually Print on Both Sides: Word prints one side and prompts you to reload the sheets.

Stack, fold and staple

Gather the sheets in the order they come out, without shuffling them. Fold them together in half, with the first page on the outside, and staple along the fold (a long-reach stapler helps). If you made several booklets, fold each one separately and stack them before binding.