There are many places where you can buy mat board, but the finest board can be found at Superior Archival Materials (http://www.superiorarchivalmats.com/ as someone already mentioned). See my article on "Advances on Archival Products," which first appeared in View Camera magazine. It describes why this board is better than other boards. Some surprising findings--that normal 100% acid-free all rag board, the kind you get from Light Impressions and other places is not truly archival, but the 100% acid-free all rag board that Superior has, because of the technology of making it, is truly archival. When I learned this stuff, I immediately switched over to the board that Superior carries. My article can be found on the Superior site, I believe. It can also be found at www.michaelandpaula.com under "Writings."
A couple things: Since the original poster enquired about discount pricing, I doubt that either Light Impressions nor Superior Archival count, as both cost about as high as I've seen.
But if you consider long-term survival of the product, and if the claims made for Superior's Alpharag are true, then the Alpharag mats start looking much more economical.
But as a chemist, I have trouble with Mr. Smith's experiment as described. The amount of test description is woefully inadequate, even for the lowest standard of a scientific test. For example, the concentrations (or partial pressures) of the components of the "pollution" gas need to be described (including the all-important humidity), whether either of the boards contained buffers (if I follow the product descriptions properly, neither was buffered, but it isn't explicit), the extent of the natural buffering provided by zeolites (as opposed to molecular trapping), the pH of the boards after the test, how long the test was done, and at what temperature.
But the absence of one test is, I'm afraid, quite telling: Alpharag vs. buffered paper. Superior makes the claim that zeolite trapping is more effective than buffering, but this claim is never tested. It's Superior's strongest claim, but oddly remains unproven.
Is a whitepaper perchance available describing the tests in full?
I was interested in getting some samples from Superior and had a few other questions I wished to discuss before placing an order. I called and a machine picked up which doesn't make give me a warm feeling and I am still waiting for a return call.
Has any one else transacted busincess with this company besides Michael Smith? If so was it a positive experience?
I am looking to change vendors; one that carries 8 ply board, as i have had it with my current contact.