I found that all my computers were printing emails from Mail.app with incredibly small font sizes. Some were so small I couldn't read them without getting very close to the paper. I messed around with the font sizes in Preferences, but to no avail. I called Apple and spent some time just messing around with trashing prefs, both of which helped me find the solution to the problem! In my user's Library -> Preferences folder, a plist by the name of com.apple.print.custompresets.plist was the culprit. I trashed the file on all my Macs, and now printing is big and beautiful!!