Hey everybody i am currently trying to render a character in Zbrush using transparency and I need to have a white background so it looks right and is nice and clear. BUT For some reason i cant get the backgound to stay white. I set it that way in the document settings and when i render it still comes out black. Please help!! The transparency is dark and doesnt look good because of it. Anybody run into this before or know a way to fix it? Thanks in advance!
http://docs.pixologic.com/reference-guide/render/bpr-transparency/
See also http://docs.pixologic.com/reference-guide/render/render-properties/
You’ll probably have to mess with the material opacity slider too 
put a plane with flat material and white color behind her, so it covers the whole document. it does not need transparency… i think where you put thw white is just for ui, not for render.
In the Color palette, choose white.
Click Texture >> New.
In the Light >> Background turn it on, then select your new texture using the Image patch.
In the Draw palette, turn the floor off if you don’t want it catching any shadows.
Render.
I’m puzzled by the answers to this. If you are using the BPR Render Pass ‘Shaded’ image then this is always black. The point is that you use this image to create a composite with a background in a program like Photoshop. The model edges in the ‘Shaded’ image are not anti-aliased [smoothed], so you need to use the ‘Mask’ image to mask the model along with your chosen background. You don’t want to use the ‘Shaded’ image on its own because of the jagged edges to the model.
If you want to set up the background in ZBrush then you can ignore the Render Pass images. Just export the final render using the Document>Export button. That will be excellent quality.
Thank you guys! Got it figured out thank you very much for the feedback!
i really like your sculpture.