A round-about method.. But you can reproduce microprint to a scale not possible by standard consumer printers with a standard consumer laser or gel printer (not inkjet) by using non-wood based paper (e.g. Rag paper). Whatever it is you want to print, print it at the smallest scale your printer is capable of printing.
Once your done, take your paper which you've printed on and soak the paper in liquid anhydrous ammonia. Take the paper out of the ammonia and let it dry. As it drys the ammonia will soften the fibers within the paper and create surface tension, and the paper will shrink a small amount (a few millimeters). Repeat this process of soaking and drying the paper and it will continue to shrink a little bit more each time. Since the paper is shrinking, it will also draw the printed characters into a tighter formation, thus reducing the apparent size of the print.
Repeating this process about a dozen times can produce dramatic results.
One negative result is the ammonia, and the tightening of the paper will result in your element result paper being more stiff than it was originally.
You do not want to use standard wood pulp paper because the repeated soaking will begin to dissolve or tear the wood fibers. You don't want to use an inkjet printer because inkjet ink is not resistant to fluids.
Alternatively, if you have access to a laser engraver, you can likely print characters as small as 0.3pt. Laser printers are generally not capable of printing characters smallert than 0.5pt and to do so demands using specific fonts which are specially designed to be readable at such small scale.
Even this Xerox specially designed digital microtext font which, the article states, is 1/100th of an inch in height. 1/100th inch = 0.71999999999999 points. - http://www.xerox.com/innovation/news-stories/microtext/enus.html