Image Credit: Terill Welch
Dating back to as early as 86 BC in China, the recipe for paper hasn’t changed much
Paper was originally made from hemp, wood, bamboo fibers and water, according to the Robert C. Williams Museum of Papermaking. Now, it’s made from a wood pulp and water mixture, with some bleach to turn it white.
A chemical compound within wood called lignin, mixed with the bleach from the refining process, will turn to hydrochloric acid as the paper ages. The acid will break down the chemical compounds within the paper, resulting in what is commonly seen as yellow and brittle newspaper clippings.
While yellow newspaper clippings and letters can be charming, yellowing prints and canvasses are not. This damage can be avoided by using acid-free archival paper, mat materials, and framing supplies.
Chemical changes happen to more than just the artwork or print
For example, not using acid-free glue when framing could yellow the back of a canvas, which will affect the value of the piece. “Any framing you have around the artwork should be archival, meaning acid-free papers, mounts, and glues,” explains Derek Smith, President of AXIS Fine Art Installation. An expert in framing, he stressed the importance of using acid-free materials to prevent visible aging.
Archival paper was invented around the middle of the 19th century
Therefore, if you are concerned about a piece from the early 19th century or before, it’s best to have its acidity levels checked.
Testing the pH levels of paper will determine whether it is acidic or not. With a scale of 0–14, anything with a pH value of 0–7 is considered acidic and 7–14 is normal. While there are kits you can use to self test, we recommend finding a professional to conduct the test, such as a local gallery or museum in your area.
Acid-free archival materials are something that every art collector needs to understand to promote the longevity of their collection
Archival paper is made of cotton fibers and has a lifespan of more than 100 years. Before the early 19th century, paper in the United States was always made from cotton fibers, which is one of the ways we have protected valuable documents. According to the Library of Congress, acidic paper ages exponentially, meaning as the rate of acid in the paper increases, so does the speed of the aging process.
Protect your collection by learning more about potential damage caused by the materials in a piece. On your next appraisal, have an expert confirm that your artwork will pass the 100-year mark.
Learn more ways to protect and preserve your collection. Download our free e-book, Essential Guide to Collecting Art, for more expert conservation and storage tips.