Nielsen Bainbridge is one of the world's leading producers of high quality picture framing products. 

Nielsen Bainbridge Artcare Matboards actively protect artwork from the damaging effects of air pollution and acids generated by the artwork itself. A unique combination of zeolites and buffers traps and neutralizes oxidizing gasses, other pre-acidic  gasses, and degradative by-products - giving Artcare boards the ability to actively protect art and photographs against attack by external pollutants and internal vices.

Most of the time though I was in classes and seminars.  Picture framing is so much more than four pieces of wood and a square piece of glass over a picture.  There is technique, physics, chemistry and biology if you really want to protect artwork.