I put together an A3 portfolio for my uni interviews, I think I had around 15-20 pieces in there all mounted on board mount (cut to A3) and the prints were 6x9 and 8x10.. or something similar, infact, you can see how I went about it here http://louise-knight.deviantart.com/art/Uni-Portfolio-81516318 obviously this one was for uni.. but I guess it could be the same principle.. I suppose it depends how you want to display your work?
I put together an A3 portfolio for my uni interviews, I think I had around 15-20 pieces in there all mounted on board mount (cut to A3) and the prints were 6x9 and 8x10.. or something similar, infact, you can see how I went about it here http://louise-knight.deviantart.com/art/Uni-Portfolio-81516318 obviously this one was for uni.. but I guess it could be the same principle.. I suppose it depends how you want to display your work?