Filler Page + End Paper
Each spread consists of 4 pages, so the total number of pages in the book must be divisible by 4. If the file doesn't have enough pages, a blank filler page can be added to ensure the total is divisible by 4.
Each spread consists of 4 pages, so the total number of pages in the book must be divisible by 4. If the file doesn't have enough pages, a blank filler page can be added to ensure the total is divisible by 4.