The Materials of Mat Board
Mat boards are a key component to any framed work of art or photograph—and they’re not just for aesthetics. Mat boards, positioned in between the artwork and the glass, are flat pieces of paper that contain an open window through which the artwork shows. They are designed to keep the glass away from the surface of the artwork while offering a more professional look to the framed piece.
Not all mat boards are the same, however. It is important to carefully consider the type of mat board you select for your frame—and not just for appeal, but for the long-term preservation of your piece.
The Types
Mat boards vary by their material, the qualities of those materials, and their intended use. Whether you are interested in preserving a family heirloom for decades to come or you are decorating your home or office with store-bought prints, you will want to ensure you select the best mat board for the job.
Cotton
This type of mat board, also known as rag mat board, is made with a cotton core and backing rather than a wood-based core. There are two types of cotton rag mat board: regular cotton rag mat board, which features face papers, or “museum quality” cotton rag mat board, which does not.
For museum quality cotton rag mat board, the process through which the cotton is colored is restricted; this keeps it safe for artwork. Because there are no face papers, the bevel, which reveals the core of the mat board, is the same color as the surface.
Regular cotton rag mat board will have a face paper, which can be colored, while the bevel typically remains white. Face papers are made from, of course, paper—because paper can become acidic, some cotton rag mat board face papers are buffered with calcium carbonate. This treatment allows the paper to more readily absorb acidic compounds, but it does not make it truly “museum quality.” In cases where certain types of photo prints can become damaged by the calcium carbonate, “unbuffered” archival mat board is more suitable.
Alpha-Cellulose
This acid-free mat board is composed of alpha-cellulose fibers, the purest form of paper pulp, and is moderately priced. Alpha-cellulose is created through mechanical or chemical separation of fibers from wood or other plants like hemp, cotton or straw. When processed, the fibers are finer than human hair and purified. Alpha-cellulose mat board can also be treated to offer active protection against harmful pollutants, but this process can be harmful to some prints. Alpha-cellulose mat board can be considered archival, though not museum quality.
Wood Pulp
This type of mat board, also known as paper mat board, is the most common and least expensive. However, paper mat boards are not recommended for long-term preservation of art pieces and should be used as a temporary solution (fewer than five years) if you want to maintain the quality of the image or art.
Wood pulp is made from wood chips processed chemically or mechanically to break down the bulk structure into smaller fibers. This material is then sent for further processing to become paper products. Paper mat boards contain lignin, a natural material found in wood. When lignin breaks down, it produces acid; this happens more rapidly if the mat board is exposed to humidity or direct sunlight. As the acid reaches the artwork, it will “burn” it and leave a brown stain. It also causes the paper to become brittle and disintegrate over time. The damage caused by acid is irreversible.
Mat Board Matters to Keep in Mind
The choice of mat board depends on your interest in protecting the artwork and the aesthetics. Mat boards intended to conserve artwork often have fewer color options as dye is sometimes harmful to the artwork; temporary mat boards are often available in a wide range of colors.
If you are concerned about the long-term preservation of your piece, you can find many mat board options to meet your needs. Mat boards are now made to not only prevent damage they may cause to the artwork overtime, but also to provide additional protection from environmental hazards. Professional-grade mat boards aren’t just for priceless works of art in the museum—they can be used to protect priceless family photos, too.