When you create a PDF you should never use Print to PDF, nor use any kind of Postscript.
Any PDF from InDesign should be exported, any PDF from Photoshop or Illustrator should be saved as PDF. If you exchange PDFs between these applications export or save as PDF/X-4.
Printing or postscript will never support transparency, therefore don't use Distiller, Printing to PDF, PDF1.3, EPS.
Don't place PNG or TIFF with vectors.
BUT, changing the paper color will not have any effect. If you need to print a different background color other than white, you should add a layer below all layers, name it background and draw a rectangle from bleed frame guide line to bleed frame guide line in the the desired color.
By chance, is there a way to export as a booklet?
I could export as single page PDFs,then arrange them on the spreads in order for a booklet - but that seems very convoluted when I could just "print booklet".
I really appreciate your help!
Imposing should be done by the printer, not by you.
There is a print booklet functionality which is VERY bad. Better is the print booklet functionality in Adobe Acrobat.
To clarify: it is ideal to compose in InDesign, then export full spreads as a PDF to maintain transparency/effects while keeping a format for local printers, who should then be able to "print as booklet" directly from Acrobat.
I really appreciate all your help! !
No, you should not do any imposing at all. It is not your task, it is the printer's task.
You don't have neither the tools nor the know how to perform professional imposing.
Export the PDF as single page PDF, in one single file, don't forget to include the bleed. Bring this file to the printer.
Ask your printer before creating the final PDF if he has specific information, as this is always a must before the production of the final file.