Standard comic books are bound by a method called “saddle stitching”.  What that means is that sheets of paper are folded in half and stapled in the center to create a booklet. One folded sheet yields FOUR pages — the front is a page, the inside front is another, the inside back is the third page, and the back is the fourth page.  One sheet, FOUR pages.  In practical terms, this means that you can’t have a comic with an odd number of pages or with a page count that is not a multiple of “four”.  Your printed comic can only have a page count that is divisible by “four”.  If you have 31 pages, for example, your comic HAS to have a page 32 as well.  It’s going to exist whether you want it there or not.