Most booklets are created with the Saddle-Stitch binding method. This economical method uses printed sheets that are folded and nested one inside the other and then stapled through the fold line with wire staples. The staples pass through the folded crease from the outside and are clinched between the centermost pages.
Pages Must Be in Multiples of Four
Folding any sheet of paper in half will create four separate panels. Because saddle-stitched booklets are constructed entirely of folded sheets, the page count must therefore be a multiple of four.
Saddle-stitched books require the page count to be a multiple of four (4)
Since each folded sheet joined within the finished booklet will form four pages of the booklet, it is not possible to create a 7-page, 10-page, or 25-page saddle-stitched booklet. The only feasible page counts for saddle-stitched booklets are 4 pages, 8 pages, 12 pages, 16 pages, 20 pages, 24 pages, 28 pages, 32 pages and so on. Even if a page within the booklet is blank, it still counts as a page