[MarjaE]

From a practical standpoint, 300 dpi in k2pdfop and 72 dpi in Quartz usually looks alright on my Mac, but not on the Kindle. I'm going to have to re-evaluate how I handle pdfs, so I can export readable versions to the Kindle without taking excessive space on the Mac.

Willus:

(1) Most applications allow users to export to pdf, or to print, where the print menu allows another chance to export to pdf.

(2-A) If you open a pdf in Preview, it allows users to export (not export to pdf), and pick pdf and pick a Quartz filter from the menu there. The existing Reduce File Size filter is unduly aggressive but there are instructions, somewhere, on how to create new filters.

(2-B) If you use Automator, one of its tools allows users to apply a Quartz filter to a selected pdf.

(2-C) If you use compression apps, these allow users to apply a Quartz filter to a selected pdf. These usually come with their own Quartz filters. PDFToolkit+ has lossless, 300 dpi, 150 dpi, 72 dpi, and minimal filters, among other tools.