Your book can’t have just any number of pages you want it to have. One fundamental restriction is that the number must be even, even if one or more pages are blank.
Each sheet of paper in a book, called a leaf, has two sides (pages). If your book has 300 pages, it requires 150 leaves. If you have 301 pages, it requires 151 leaves and you'll have one blank page after page 301.
It’s pretty common for books to have more than one blank page at the end (or even in the beginning). Additionally, the signatures (large sheets of paper that are printed on before cutting and binding) may dictate that books be composed of multiples of specific numbers, such as 4, 8 or 16. If you come up short or long, you’ll need to write more words or stretch the book to fill up blank pages, or cut words or tighten-up to use one less signature.
You probably have a “target” length for your book, and maybe you’ve missed the target.
Perhaps you think that in order to justify your price, you should be providing at least 300 pages, but you only have 289. Maybe you think a 300-page book will overwhelm some people, but you’ve come up with 311. Maybe your printing budget and cover price will cover a 240-page book but not 250 pages. Maybe you want to offer more pages than a competitive book. Maybe you want a thicker book so the title printed on the spine will be bigger.
There are many ways to reduce the number of pages without cutting important words, and it’s also easy to increase the number of pages even if you have nothing more to say.
Some of the tricks for increasing or decreasing the page count can also improve the appearance of a book by eliminating orphans or other typographic misfortunes, such as two or three words that make a chapter take up an extra page.
Try saying things differently. If you wrote “increasing or decreasing,” space could be saved by substituting “altering” or “modifying” without significantly changing the meaning.
Take advantage of shorter words and contractions. “Pasta” takes up less space than “macaroni” or “spaghetti.” “Group” and “club” are shorter than “organization.” “Can’t” takes up less space than “can not.” Sometimes eliminating just one or two characters can eliminate a page.
Change to different margins. Even using 1/16 of an inch less can save many pages.
Use fewer or smaller illustrations, or pack you type closer to them.
Use smaller size type, either in the whole book or in sections like the table of contents or bibliography. Even a one-point difference can save a lot of pages if you make the change in the whole book. Be careful not to sacrifice readability.
Use a narrower typeface.
Make bulleted lists flush-left instead of indented.
Skip middle names.
It’s equally easy to pad or stretch the book to make it longer. Don’t be obvious if you have to do this. Don’t use 16-pt type instead of 11. It didn’t fool your history teacher who wanted 10 pages about Abe Lincoln and you only had enough words to fill nine pages with normal size letters. You won’t fool people who review or buy your book, either.
If you have to stretch, use a combination of techniques, in moderation. Don’t use one in excess. Try some of these:
Always start chapters on a recto page.
Put more white space around photos, charts, tables and illustrations.
If you just want a bigger spine to print your title on but don’t care about more pages, use thicker paper. Cream (a/k/a “crème”) is usually thicker than white.
Add more photos, charts, tables and illustrations.
Make photos, charts, tables and illustrations larger.
Start chapters in the middle of a page instead of at the top.
Put quotes or helpful hints on individual pages.
Break up paragraphs into smaller paragraphs.
Add some words.
Use longer words.
Define technical terms when you introduce them.
Have more front matter, such as a half-title page ("bastard title") ahead of the title page. I used to think It’s a stupid waste of paper, but I've used it for some recent books. It's a good place for autographs.
Use bulleted lists instead of paragraphs with many items separated by commas.
Increase the spacing between lines in a list.
Spell out some names instead of using initials or abbreviations: “John Pierpont Morgan” takes up more space than “J. P. Morgan.”
Include a summary at the beginning or end of chapters and sections.
Include a bibliography listing additional resources.
Put an order form in the back of the book.
Use pull-quotes (also known as a lift-quote or call-quote). They’re excerpts from the book printed in a larger typeface and inserted in the page, surrounded by white space, with the main text wrapped around it. It’s difficult to read a sentence that is broken by a text box or illustration, so keep it to one side. If you have two columns, it’s OK to center it.
You can also make a book seem longer than it really is.
In many books, sections of the front matter have no printed page numbers ("blind folios") or they display roman numerals. If you include the table of contents and introduction in your overall numbering sequence, you might be able to make ther last numbered page reach 307 instead of 297, which could give you an advantage. Don't put numbers on pages before the table of contents. Be aware that booksellers and distributors may show different page totals than you come up with.