I got a gripe with most normal printers. They just don't have the detail that I sometimes want. I print out line art to color. It may sound silly but it is really relaxing. So how much can you get out of it?
That's depending on your printer. However, any "usual" printer has its limit at around 6-7pt. Beyond its raster is becoming too unprecise. There are special printers which are built for microprinting but those are most likely industrial based and way more than I would want to spend.
- Digital: Professional/archival/photo printers of 2400-4800 DPI can handle very small details.
- Analog: Flexograph, lithograph or even full digital flexograph press.
I have heard if you want really fine prints with normal equipement you need to splurge on very high quality glossy or "calendered" paper that has an extremely smooth printing surface, not copy paper or cheap cardstock. Which is worthless for my needs.