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The book is a duplex mode when the number of pages is odd I just need to add the new PDF file with the colophon, but when the quantity of pages is even I need to add a blank page and the last page need to be the PDF with the colophon.
Note: The colophon is really just a book publisher's logo added to the bottom of the last page in a book block.
Although this can be done in a number of ways, the simplest implementation is one that would leverage the rules within the Insert Pages component.
The workflow itself is pretty simple
The first Insert Pages node adds the page with the colophon to the end of the book block
The second Insert Pages node makes the document a multiple of 2 pages by adding blank pages (if needed) before the last page
After this the book is ready for imposition, pressmarks, etc.