Nate,
The big problem with using z-brush for 3dprinting is the high poly counts you get when doing fine details like wrinkles and such that makes a z-brush model stand head and shoulders above all others. I use z-brush and when you start to get into level 4-7 subdivision for those details you start to surpass what your 3d program can handle. That is why z-brush is usually used to generate the modelled detail as a displacement map instead of direct export to .obj.
The 3d printing as you know does not support bump and displacement maps so you would have to bring the high detail obj straight from z-brush. After converting your tool(model) to a mesh you can export to obj in z-brush. Here are a few screen caps of a doodle(380000 poly) in z-brush, then exported in obj to hex, and a carrara render.
This is a simple object with not a high poly count in z-brush standards(1mil+). You can also bring your obj into z-brush to add texture to your existing models. I hope this answers your question.
