I believe that for dot-matrix printers, the more lines you have, the harder it is to print, because for most dot-matrix printers the CPU has to render that in a page before it can send it to the printer. (I.e. dumb printer, doesn't help the computer do any printing by having "macro" commands for lines.)
So if you have reports with printed column dividers, visible margin boundaries, and the like, you face a computational slowdown. Remember also that your printer driver IS involved in report generation - because Access looks at the stored capabilities of your default printer to define how it will print something. And in fact if you don't HAVE a default printer, you can't display a report. That's because Access reports TRY to show you what you will see a la WYSIWYG - and if there IS no printer, it doesn't know how to show you the report because it doesn't know how to build it.
Faster still? If you have a way to migrate reports to a shared printer, that would help. There IS a way to print to a file, but there are issues with setting that up because you STILL have to tell it what kind of printer you will be using.