What is the Difference Between Acid-Free and Archival?

We often get questions about what the difference is between acid-free papers and archival papers.

Acid-free papers are made using alkaline paper making technology. This means the pH of the pulp that is used to form the paper is above 7 (neutral). The paper is also buffered with an alkaline reserve, such as calcium carbonate, to neutralize acid compounds absorbed from the atmosphere or formed through natural aging.

pH Scale

Although there are no universal standards in regards to what makes a paper archival, there are some generally accepted properties. In addition to being acid free, the paper should contain no groundwood or unbleached pulp, meet strict limits on metallic content and be free from optical brighteners which artificially make the sheet whiter.

If you are looking for the ultimate in permanence, we recommend acid free surfaces made with 100% cotton.

Papers in our 500 Series line such as 500 Series Drawing, Bristol, Museum Mounting Board, Illustration Board, Charcoal, and Mixed Media are all 100% cotton and acid free.

Furthermore, our Museum Mounting Board meets the Library of Congress Standards for Archival Properties.

In addition to your choice in paper, don’t forget environmental factors. They can be just as important in ensuring the longevity of your work. Light, heat and humidity all have an effect on paper. Sunlight and ultraviolet light can cause fading and brittleness. Too low a humidity can cause paper brittleness, and too high a humidity increases the chance of mold. The lower the storage temperature of paper, the longer it lasts. The life of paper is doubled with every decrease of 10°F. Cycling (temperature/humidity fluctuations) weakens and breaks down paper fibers by causing fibers to expand and contract.

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