When you create your pages, you probably start with single 8-1/2 x 11 pages, but side by side.
When you turn one of the 8-1/2 x 11 pages to 8-1/2 x 15, you need to use the Page tool. When doing so, use the Reference Point widget (circled below) to set the upper left corner of the page.
When you make a PDF file as a spread, it should now look like this:
Thank you, Steve. I am going to review this now to determine if I can edit an existing page to accomplish this or if I have to create a new page. In either case, this appears to be exactly what I was trying to accomplish. Thanks again.
Works exactly as you describe and is a big help. However, this applies as long as spread is made first. If spread is undone and then re-created, the alignment returns to center. Is there any solution to this? Thank you.
I'm not sure what you mean by, "If spread is undone and then re-created".
What steps are being done in between so I can try to match what you're doing? Do you mean the pages are being moved around (which you can do with the Page tool)?
As I stated in my first message, I create all documents as individual pages (fig 1), then only create reader's spreads (fig 2) for PDF soft proofing to my customers. I create the file as single pages as I, ultimately, use imposition software to execute printer's spreads at plating. During the course of project development, I may need to switch between individual pages (fig 1) and reader's spreads (fig 2).
1. It is only when reader's spreads (fig 2) are created from individual pages (fig 1) BEFORE Page Tool is used to change any page size (fig 1), the resulting PDF page alignment is aligned to the reference point (fig 3).
2. If reader's spreads (fig 2) are created from individual pages (fig 1) AFTER Page Tool is used to change any page size (fig 1), the resulting PDF page alignment is centered (fig 4).
3. If reader's spreads (fig 2) containing multiple page sizes from step 1 are reset to individual pages (fig 1), PDF page alignment will again be centered (fig 4) the next time reader's spreads (fig 2) are created from this file.
Is there a way to set the reference point for alignment AFTER Page Tool is used to adjust page size but BEFORE spreads are created? Thank you.
I don't know of a way to do what you're trying to do. It's a somewhat unconventional approach, and I don't think you can do what you want, as far as I can tell.