Why Museum Framing uses 100% cotton rag mats and not “acid free” mats

When people come in for framing, they usually ask me if I use “acid free” mats.  When I say “no”, they look at me like I came from another planet.  The term “acid free” is a misnomer as it is misused by both framers and customers alike.

Without sounding too technical, acidity is measured on a pH scale.  Neutral pH is equal to 7.  pH of 6 is 10x more acidic then a pH of 7.  Conversely, pH 8 is equally less acidic, and known to be more alkaline. Regular “acid free” matboard has a neutral pH of 7, whereas cotton rag matting, has a pH of 8 to 9, which is superior in makeup.

The mats we use are called “rag” mats, made of cotton fibers and the finest on the market. This is similar to the durable paper that the colonies used on most of their currency.  As a collector of historical artifacts, I can attest to the longevity of our colonial paper money through the condition of those being traded today.

When most people here “Acid free”, they think that the framing is museum quality.  That the item being framed, diploma, print, photograph, whatever, won’t be subjected to any deterioration. And, though, “acid free” should refer to 100% cotton rag mats, manufacturers and distributors of other matboard use this buzz term to promote their supply of wood pulp paper mats.

How can that be?  Easy.  Standards are set up certain companies that allow for certain standards.  Unfortunately, those standards set are minimal, just like minimal standards set for some of our food, cars, etc.  Thus, when advertisers state a strong characteristic about the product, it can be either misunderstood or worse, misleading.

The author has seen numerous cases where artwork has been damaged due to the presence of acids from the pulp in the so-called “acid free” mats. As a matter of fact, a common characteristic of the presence of acids in these matboards is a stain that appears over time around the perimeter of the artwork.  This is commonly referred to as a “mat burn”.

The claim of framers and suppliers make regarding these mats is that they have been chemically treated to a neutral pH.  Meaning artificial chemicals bleach the ingredients of the matting to slow the process of “mat burn”.  With the eventual presence of light, heat and humidity, environmental factors kick in and cause the materials to break down, thus leaching contaminants onto your art.

Framers carry these “acid free” mats because they are cheaper than 100% cotton rag mats. Plus frame shops believe in the appearance rather than the archival preservation of items being framed.

This author strongly disagrees as you can have both an excellent presentation and still have conservation framing methods.  In the past 10 years, more popular colors have been introduced to entice framers to use cotton rag matting.

One note of caution is that some manufacturers produce matboards that look like rag mats, but have inferior qualities.  Materials that WILL harm your artwork over time.  Many frame shops buy these because they have the look, but at a lower price.

Truth be told, 100% rag mats cost the framer only sightly more than paper wood pulp mats, also known as “regular matboards”.  But, many frame shops have a strictly business mentality that means maximize profits at the least cost.

Pity, as I believe maximize profits by taking care of your client base to they can return and tell their friends.

Document previously framed with "acid free'" matting

Document previously framed with “acid free'” matting


Categories: Alexandria framing, art, conservation care, Conservation Framing, custom framing, Diploma Frame, Framing, framing awards, Framing military medals, Military Framing, Museum Framing, Navy | Tags: , , , , , , , , , , , , , , , , , , , , , , , , . Bookmark the permalink. Comments are closed, but you can leave a trackback: Trackback URL.