Really, using rubber stamps is a form of printing, so all those rubber-stamping enthusiasts who frequent the aisles of Michaels and other craft stores are really printers. To qualify as printmakers, though, I think they have to be using rubber stamps they cut themselves (or at least ones they had made from their own art).
But making your own rubber stamps (aka tiny printing elements) isn't really that hard. If you can draw passably and handle a craft knife (or lino-cutting or wood-carving tools), and if you can either think backwards or figure out how to transfer a right-reading image to another surface so it comes out backwards, you can make your own rubber-stamps. If you're already a printmaker, all you have to do is think smaller, and maybe get used to a softer medium than, say, lino.
Those white plastic erasers (the ones that are actually useful for erasing pencils marks, unlike those horrible pink ones) are the perfect medium. They come in various sizes, and you can even buy large sheets of a similar material at art stores that's intended for easy printmaking. Unless you intend to go really big, though, I'd stick with erasers, because you can buy them cheaply (try your local dollar store, even).
Here are a few I made over the years (along with an eraser of the most common size for scale). Most of them were cut with just a knife, though for the tiny details on the nautilus cross-section, I did resort to my smallest v-cutter that I use for linocutting, and I used a shallow u-gouge to clear out some of the open area.
You can also see that I've mounted some of them. I'll probably cut some masonite to mount the rest on, as having a solid support helps reduce instances of the flexible eraser bending and printing areas that shouldn't print.
I'm planning to do more shell cross-sections and other "specimens" for some books I'm making (if you check back a few posts, you'll see where I used the nautilus on a recent book). I just need to buy some more erasers!