save multiple Indesign pages as one pdf

Although you posted this in an Acrobat forum where an InDesign question is less likely to be responded to, the fact is that there is no built-in method of exporting PDF from InDesign in the manner you describe, i.e., multiple pages to a one page PDF file, with one exception.

If you define your InDesign document such that all the pages are in a single spread, you can export the document as “spreads” in which case the pages will be exported as a single page PDF file with the pages next to each other in parallel, in other words, this allows 1 by n page imposition horizontally.

If you need more complex imposition of n pages of your original document on a single PDF page, you need to post-process the document in Acrobat. The most convenient method of doing such page imposition (n by m imposition) is via third party plug-ins to Acrobat, two examples of which are Quite Imposing Plus and PDFSnake, neither of which are inexpensive, but safely perform the functions required. There are other manual hacks you can perform in Acrobat such as creating a new PDF file of the size you want and placing individual pages into new layers at the positions you want and then combining layers - a very time consuming and error prone process.

Another hack which I don't recommend is to create a new InDesign document which a page size accommodating all the pages of your original document. You can place pages from your original InDesign document into the new document or place the single pages exported from that original InDesign document into the new InDesign document. Then, export a new PDF file.

In summary, I would recommend the Acrobat plug-in approach. It is safe, high quality, and easy to use compared to the other hacks.

          - Dov