Acid-Free and Archival Paper

 

In art, archival papers are absolutely important if we want paper-bound works of art to stand the test of time. In business, archival papers might not seem as important (considering the increasing reliance on digital documents), but they still serve a purpose. This especially holds true for legal, historical, or other significant documents.

All types of paper can deteriorate over time. There are basically two ways in which deterioration can be slowed, if not eliminated. First, the production process must remove those things in paper which cause it to change. Secondly, purposeful and careful storage and handling methods must be observed.

Why does paper deteriorate?
While the actual process is quite chemically complex, the simple answer is that paper is made of wood pulp. Wood pulp naturally contains lignin – an acidic substance that makes up the cellular walls in wood pulp. It’s this acidic element that is the main culprit in paper deterioration. That deterioration can be accelerated by the lignin’s exposure to other natural elements, especially sunlight, water, or just time itself.
You’ve probably seen a yellowed, brittle newspaper that has been left outside. Even if it was just new last month, the combination of excessive lignin found in newsprint and the fact that it’s been exposed to the elements, means that the deterioration process was extreme. It’s yellowed, stained, and might even begin to crumble.

Wood pulp can be chemically treated during the paper-making process to remove some, or all, or the lignin, thereby lowering the amount of acid in the paper stock.
It’s worth noting that even high-quality papers with low-levels of lignin can suffer when they are not stored correctly for long periods of time. Semi-archival papers that are stored in folders made of cheap paper, or even in untreated wooden drawers or cabinets, will deteriorate faster than they normally would just by being in contact with those other, high-lignin content surfaces.

Acid-Free and Archival Papers
The natural acidity of paper is measured by its alkaline, or pH, levels. The aforementioned newsprint, for example, has a very high pH level. In the 1930s, the connection between the alkaline levels in paper and their archival properties was discovered. By the 1950s, steps were being taken to remove the acid from paper that was required for archival purposes.
While there are various standards for “acid-free” paper, it’s generally high-quality papers that have either had all the lignin removed through chemical processes, or papers that have exceptionally low pH levels that are considered acid-free.

The term “archival” is a universal term, and can be used somewhat freely by paper manufacturers. However, in most cases, “archival” papers are deemed stable because they are usually acid-free, contain no unbleached pulp and are free from the optical brighteners sometimes used to whiten the paper stock. While those kinds of papers definitely last a long time without any signs of deterioration, truly archival paper is almost always made from cotton rag instead of wood pulp. Therefore, it naturally has very little, if any acid in it.

The types of paper available to you for business purposes are wide ranging. If you are concerned about the durability and stability of the paper, read the packaging. Begin by seeking out acid-free paper. Many high-quality papers might also use a combination of cotton rag and wood pulp. The balance between the two will give you a good idea of how you can expect it to age.

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