Since pages in a book are two-sided, it makes sense that the total number of pages in your book (counting blank pages) be an even number (divisible by 2).
The last page facing the inside cover, must be completely blank so that we can add a barcode that makes it possible for us to match the interior bookblock and the cover during the manufacturing process. We also add manufacturing and batch information, to help us investigate any production issues that may occur.
Your file does not have to include this blank page at the end, we will make the adjustment. A blank page is defined as totally absent of any content; this includes headers, footers, page numbers and be sure to not press the space bar.
Books that are 6.14 x 9.21 (234mm x 156mm) and smaller will be printed in six-page (three front/three back) single – sheet signatures. Books that are 6.69 x 9.61 (244mm x 170mm) and larger will be printed in four-page (two front/two back) single sheets signatures. This may also cause blank pages to be added.