cool aid acid test*

Acidic paper items deteriorate over time. In a perfect world all books would be made of alkaline paper which lasts ten times longer than the customary acidic paper, which crumbles after about 40 years. Permanent paper such as those sized with a buffering agent like calcium carbonate has a life expectancy of at least 500 years or more. But alas no perfect world for us.

The wood pulp fibers in commercially produced papers since 1850s are an unstable component that cause an acidic reaction. Many papers produced in the last century were made with an alum rosin, which is acidic. Acidic paper loses its strength, becomes brittle and is unable to support itself. Materials with a pH of 7.0 or higher are considered acid-free. Acid-free materials can be either buffered or unbuffered. Buffering agents like magnesium oxide or calcium carbonate typically raise the pH of a material to 8.0 or higher. A good rule of thumb is to assume all paper items are acidic unless it is clearly labeled or you have tested it.

PH testing can be done with a pen, a marker similar to the ones they use to test money.
Lineco pH Testing Pen – With a simple swipe you can distinguish between safe (neutral or alkaline) paper and board and acidic materials. Simply draw a small line on the
material you wish to test. The chlorophenol red indicator solution in the pen will turn purple on any paper with a pH of 6.8 and above. A clear or yellow color indicates the material is probably unsuitable for conservation purposes. Paper can be respectably long lived if is pH is as low as 6.0, especially if is well made and carefully used and stored. In order to last for centuries in today’s polluted air, it must have an alkaline reserve and this usually means a pH of 7.0 or greater. Unfortunately the mark from this pen does not fade entirely. If anyone knows of one that DOES fade, please let me know.

There are deacidification sprays on the market for consumer use like • Bookkeeper® Deacidification Spray (magnesium oxide) and • Krylon Make it Acid-Free Spray (calcium carbonate). The aerosol carrier evaporates quickly leaving behind a layer of the buffering agent which reacts with the moisture in the atmosphere to create the deacidificant. I have read the exact chemistry that occurs several times and I can’t simplify it any more than that. Let’s just call it magic.

It would probably be best to scan or photograph the item BEFORE spraying, as there is a powdery residue.

for further reading :
• from The American Institute for Conservation – Observations on the Use of Bookkeeper® Deacidification Spray for the Treatment of Individual Objects

• from Conservation Online – professional articles on mass deacidification

*apologies to Tom Wolfe

see? who needs that nasty old job anyway?

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