I have put up a New Article on my Personal Blog
Lighting The Pixel Perfect Isolation about how to set up and control your lighting in the studio to obtain a perfect white background.
It is not a light read but if you are interested in creating images such as these for stock then I think you will find the techniques and lighting chart provided useful. I would post it all here but to be honest it is a 5 pages read plus illustration and due to the limitations of image posting in the DT Blog I cant make it work here.