i tried searching for this, and asking it in a thread, where i thought the person was asking the same question…
what i want to do is do a quick polypaint in zbrush on a 3d object, and then to convert it to a texture to export it and fine tune it in PhotoShop, so i can bring it back into zbrush.
Is this possible?
I did a search and found loads of similar topics. You can also find the info you need in the online docs. You will need to make your UV layout in another application though. The UVs ZBrush makes won’t work for editing in PS.
http://www.pixologic.com/docs/index.php/Baking_PolyPainting_into_a_Texture_Map
-Dustin
crappioca, i only have zbrush and photoshop, i guess im gonna have to find a way to obtain a couple thousand dollars, for another program, if i want to be able to do this 
Roadkill UV
free unwrapper.
Or Headus for $300. It looks like a Buick, but it drives like a Cadillac 
I’ve also heard good things about Unfold 3D.
Step by step
1.poly paint to your model
2.Give it AUV tiles
3.Convert your poly paint to texture (col-text)
4.Ditch your poly paint and select your texture
5.Use Zapplink to go into photoshop, and paint
6. When you re-import the detail will transfer to your texture rather than your vertices
Insanely simple
small_orange_diamond
small_orange_diamond
thanks guys… i’ll give those free unwrapping programs a shot and see what happens… it looks like zapplink still isn’t up for mac tho, but i’ll see what happens
fair enough but just so you know, you can export the document after dropping into projection master, open that document in PS, paint then re-import.
Of course it helps to have a few passes such as alpha, shaded.
UV layout is the best, however the free alternative is road kill.