Hi guys, I use Poser to get my base mesh and then I export to Zbrush, use subtool extraction and then usually I go to Subtool master and merge all, deleting the old subtools. Then I export the merged mesh as an stl in 3d print exporter. SO far I've had mixed results, half of my models have no problems after being fixed in netfabb and others cannot be fixed - "surface not orientable" in netfabb and shapeways errors produce "mixed winding triangles" errors. After one of the moderators looked at my model that I was having problems with he said that there were holes in the face from the teeth and that all the clothing meshes were seperate from the base mesh and they needed to be booleaned together - little help?
In ZBrush with both sub tools visible, go to the SubTool menu and click on ReMesh All. Make sure X, Y and Z are not selected and the ReMesh Resolution bar is set higher. This will definitely make your model water tight.