Why do some LDS books have empty pages at the back? I just finished reading a book that had all of five empty pages between the end of the story and the back cover, and it got me thinking. Now I'm checking all my LDS books. Some don't have any empty pages, some have two, and some have three. There's no consistency among books by the same publisher, and no reason for it that I can see, so I was just wondering.
This is an easy one. Books are printed in "signatures"--that's one big sheet of paper printed on both sides, then folded to create the individual pages of the book. The most common signature holds 32 pages, so the number of total pages in your book will be a multiple of 32. Sometimes you can go down to 16, or 8, but that's not as economical.
So let's say the text of your book is 250 typeset pages. It would be printed on 8 signatures of 32, giving you a total of 256 pages. The extra 6 pages would be used as the title and copyright pages, table of contents, about the author, etc. But let's say your text only uses 245 pages. You'll have extra pages that you either need to fill up or leave blank.
I try never to leave extra blank pages. It's a waste of space. I'll add a half title, or a page or two of endorsements, or promo for the author's next book, or something to fill the pages.