How to produce VDP output of document containing spreads or facing pages
If you are using the DesignMerge PDF or Optimized PostScript Driver, set up the facing pages document as you normally would and merge just as you would any other job.
However, if you are using the DesignMerge PPML or Creo VPS Print Driver, please note these two Drivers produce output by page, not by spreads. Therefore, for best results, turn off (uncheck) the Facing Pages setting when laying out a document. For a document where you would normally set up facing pages to print spreads, instead set the document page size to be the same size as the "desired spread." Then treat each page in this document as a "printer spread," placing all of the content for "the spread" on the single document page.