It sounds like you are using the "Export View" function, right? In order to get more detail, set the resolution of the export to something higher than what it defaults to (which is the same size as your screen). If you go to 3000x3000 or so, you should get a pretty detailed map for printing. You can figure out the DPI you're printing, the size of the paper, and do an exact export that way, too. Most computer should be able to go up to 7000x7000 or so.
Hope that helps.