I’m pretty much anewbie with ZB so apologies in advance.
I have modeled an object in ZB and would like to export it as a psd file to comp into a 2d image. Is there a way of doing this without its background. This is probably pretty obvious but I can’t seem to do it 
Not sure myself, don’t think there is a way. All you can do is change the color, make white and then just do some major lassoing in PShop. Sorry bro! 
try changing the document color to black, then do a separate render with your model using either the flat render or the flat material set to white, once you take this image into photoshop just use the magic wand tool to choose the black and use cut.
I think you can use ZApplink for this.
just position your model the way you like it to be positioned in your composition and hit the ZApplink button and ,once in photoshop disable ZShading layer and Use copy merged on to copy your model with the color and transparent background and thats it. the background should be ttransparent around your model this way.
allso if you have photoshop Extended you can import the obj file from zbrush in to photoshop and position the model as youd like to in your composition.
good luck
Many thanks for the help. I used z-app link in the end and it worked fine. I have photoshop extended but I wanted the lighting from ZB so Z-app was just fine