My dilemma
So I have some renders and do not want to print the whole body I just want to 3d print the head from the neck down, how can I separate the head so I can then save it as an obj then I can convert the file? I then want to start 3d printing the full size head and see how it turns out from the render I am using, any suggestions would be great, and sorry if this is in the wrong thread I did not know where to put it.

Comments
Well, it's a question not a dilemma. If you hide the unwanted body parts those should not export as OBJ, but then you will need to cap the open neck (I assume you mean the head from the neck up) - it's going to involve using a modelling tool anyway, so it may be simpler to use a cutting plane or Boolean on the whole body, or at least the upper body, to give you a flat base to the print..
I would like to keep half of the neck as I think once it is printed I can make her into a realistic head much easier, how does one use a cutting plane or boolean as I have no idea what those are at the moment, thanks for the initial reply I hope I can figure this out soon, as the printing process is going to take some time.
How you cut the model would depend on the modeller you used.
Is blender any good?
Meshmixer by Autodesk might help
its free
I want to slice some models for printing too but am probably going to do so using boolean in Carrara vertex room.
Blender should be able to do it too but I would not know how.
Here you go http://youtu.be/VuF4nDwA1xo
I will try figure this out and use blender and if I do not know how I will use meshmixer and then if I do not know how I will pay somebody LOL