Getting to Know the Different Types of Matboard
The Five Types of Mat Board (at a glance)
• Alphamat Artcare by Bainbridge is a conservation quality archival mat board made of alpha cellulose fibers. 100% acid and lignin free throughout.
• Rag Mat Board by Crescent is an acid free, lignin free cotton core mat board. Archival quality. Face papers are acid neutralized.
Is Regular Mat Board Safe for My Artwork?
Regular mat board is made of wood pulp based paper. Untreated regular mat board could be a threat to art but it is no longer possible to buy mat board that is untreated. All paper mat board manufactured for picture framing is put through a bath of calcium carbonate to neutralize it against the acidity that occurs when lignin, the binding polymer in wood, breaks down.
Neutralization renders the acid content harmless for a period of time, perhaps as long as a hundred years. Today, all Bainbridge regular mat board (called Paperboard) and Crescent regular mat board (called Decorative Mat Board) has been acid-neturalized in this way.
The problem with acid is that it migrates. Once it seeps out of an acid bearing material it can contaminate anything it comes into contact with. Museums and others who handle valuable heirloom art are concerned that while neutralization can keep acid neutralized for a period of time, once it breaks down it becomes the source of the problem, not the barrier against it. For them mat board should be a barrier and hindrance to acid migration. The way to achieve this is to make mat board out of a material that cannot become potentially acidic in the future.
Museum Rag 100 is that mat board. Making a board entirely of cotton is pricey, which makes this the most expensive mat board available, but also the safest.
Museum grade rag is recommended for rare and valuable art that requires protection for generations to come.