My Git Book Writing Blog

Divisible by 8

Janet Vail, who is overseeing the production of this book, sent me this note about the final page count.

Chapter 20 currently ends on page 344. The front matter will
add about 20 pages, and the index will add another 8 to 10 pages
for a final estimated page count of 368 or 376. (The final page
count must be divisible by 8 for printing.)

I spent a few minutes pondering that parenthetical. The page count must be divisible by 8. Why?

I spent a good amount of time pondering the printing process when I worked on a student magazine in college. A lot of that started coming back with her e-mail.

The pages in a magazine or a book are printed on a large sheet of paper called a signature. There are 8 or 16 book pages on this large sheet of paper. After folding and cutting, this signature forms a block of 16 or 32 pages.

I found a great picture and explanation of the concepts here:

The 8 page imposition is shown below. The imposition is the placement and direction of pages, such that when folded and cut the pages are in the correct order. The website also shows that larger signatures are possible.


I thought two things: 1) printing software to properly layout signatures would be challenging, and 2) the book is very nearly done!

Thanks for reading everyone!