Page numbering in DesignMerge output
For PPML, VPS, and PostScript output, we create a “workfile” document, which is a duplicate copy of the original file. It is the workfile document that is merged and printed so the original version of the file is never touched.
In this workfile document, we replicate the pages of the file to try and build up a 5-page-set document. As an example, if you start with a 2-page document, the size of the workfile will actually be 10-pages. This is so we can process more than 1 record at a time. In the case of a 5-page workfile, we are processing 5-records at a time, which can improve processing times.
The drawback to this is that if you are using InDesign automatic page numbering for a job, then when the workfile is built, the page numbering will be changed across all pages in the workfile. In the previous example, for a five-record job (resulting in a 10-page workfile), the pages would be numbered 1,2,3,4,5,6,7,8,9,10 (instead of 1,2,1,2,1,2,1,2,1,2).
When we detect that InDesign automatic page numbering is utilized in a document, we automatically set the workfile size to 1, meaning that it will only process the same amount of pages that were in the original document. There will be no difference in output under this scenario, but because the workfile size is smaller, you may experience slower overall performance for the job.
The workaround is that instead of using InDesign automatic page number, just put in a static page number on each page.