We bought following background paper roll carton for product photography and we are very pleased with our setup and results, especially after post processing.
Background super-white: http://www.wexphotographic.com/buy-tetenal-super-white-background-paper-roll-1-35-x-11m/p1538844
We compared this super-white to basic printer paper, which is a little whiter and slightly noticable on screen before post-production.
To get the best white results without post-production we are thinking about buying a large cheaper din a0 printer paper roll, and using that on top of the carton.
Are there any disadvantages using printer paper, since it is chemically enhanced to get pure white, reflecting more of uv-light?
Our photo table and lightning setup is like following (just with paper carton background instead of plastic):