There's a saying familiar to people who form collections: The current owner of an item is only its temporary caretaker, with the obligation to see that it leaves their possession in the same condition as when it arrived. 

In other words, it's our responsibility to protect our newspapers, documents, postcards, comic books, stock certificates, etc. from harm from any source, and, to the best of our ability, from the ravages of time. If that sounds overwhelming, rest assured that it's not as hard as you might think, using a few simple and easily remembered techniques. 

Paper deterioration is a complex process that you could spend years trying to understand. It is made especially complex because various destructive processes interact with each other. (Click on the image for a larger view of serious paper deterioration..)

You can go a long way toward preserving your collection by appreciating these major problems that destroy paper.

	Acid
	Light
	Heat
	Moisture
	Mistreatment

In the short term, mistreatment is a bad thing. Obviously, you want to handle your paper carefully. You want to protect it from tearing, folding, and rumpling. As far as mistreatment goes, clear plastic holders help immensely.

No matter how careful you are, your paper will still deteriorate if you do not minimize the effects of acid. Over the long term, I suggest acid is the greatest single threat to paper collectibles.

Acid dramatically shortens the life of paper. Even extremely weak acid. Even the very best paper.

Understand that the acid we are talking about is not in liquid form. The acid that attacks paper is really nothing more than free hydrogen protons that move freely throughout the fibrous structure of paper. And very freely between pieces of paper. If you have ever seen what happens to a piece of good paper that is stored with newspaper, you will understand the severity of acid destruction.

Most acid deterioration probably comes from other paper. Specifically, most acid originates with the lignin that comes from wood pulp.

Practically every kind of paper carries some acidic content. In fact, unless you specifically buy "acid-free" materials, you will find significant amounts of acid in all sorts of storage materials, including backing boards, cardboard, manila folders, storage boxes, matting, drawer liners, and envelopes. Even from wooden cabinets and boxes.

Once you appreciate the danger, you must avoid letting your certificates contact anything that might contain acid. That means not letting your certificates contact ANY other paper.

Acid can also come from environmental sources such as acidic atmosphere. As deleterious as that might seem, I suspect that atmospheric effects are minimal compared to contact with other paper products. I have no idea where cigarette smoke might figure in, but I cannot imagine it being beneficial.

Fountain pen inks tend were be weakly acidic. Given sufficient time, ink pen marks, such as in signatures, will eat completely through many papers.

Your own fingerprints will damage your certificates. Wash your hands all you want, but if you don't use gloves, a year or two later a yellowed fingerprint will be visible to the naked eye. 

Measuring acid.

Archivists have special instruments to measure acidity, but I don't. A few years ago, I performed an experiment in my kitchen to determine which kinds of papers were acidic and which were not. I put drops of water on all sorts of typical paper used by stamp, paper money, and certificate collectors. I let the water set a minute or so, and then measured the acid content with pH paper. We're not talking rocket-science here. And I didn't want to pay some lab to do it for me. So I will never say my results are completely scientific.

But, here is what I found. Neutral water has a pH of 7 and any pH lower than 7 is acidic.

I realize that the pH values of various papers varies among manufacturers. But you can see that all the papers I tested were somewhat acidic. Most importantly, some of the "best" papers were the most acidic.

Take the "black stamp book paper" listed above. That was paper that came out of several expensive stamp albums. All the pages were acidic. Some were almost as acidic as newsprint.

Surprisingly, I found the same thing with glassine envelopes. The are the standard storage envelopes used in the stamp hobby. I contend that neither storage method is safe UNLESS you buy the really good stuff. And the good stuff is expensive.

One final thing to understand is that the pH scale is logarithmic. In other words, a pH of 5 is ten times more acidic than a pH of 6. A pH of 4 is 100 times more acidic than a pH of 6.

With time, light breaks the structure of most chemical compounds. Even plastic. By comparison, paper is terribly easy to destroy. Yet, the destruction might not be as simple as breaking chemical bonds. It may be more like a multi-step process, whereby light first causes photo-degradation. That degradation, might go on to release trapped acids, which in turn destroys paper even more quickly.

Obviously, light causes fading, especially in red-based pigments. Light in the ultraviolet (UV) part of the spectrum is most damaging because it is more energetic than visible light. Up to 25% of sunlight is ultraviolet light. Light from ordinary fluorescent lights can emit up to 7% of their energy in the UV spectrum.

There are special films and glasses available that limit the transmittal of UV, particularly from fluorescent lights.

Avoidance is the cheapest and most effective method of protecting your certificates. Avoid UV. Use ordinary, old fashioned incandescent lights which do not emit UV.

If you encounter a faded certificate, you should automatically expect deeper, hidden chemical deterioration waiting to appear a few years into the future. Moreover, if you see a certificate that is 'sunburned,' yellowed, or browned, you should expect related brittleness and early disintegration. 

Heat speeds up chemical reactions. If there is any acid in your paper (and you can be assured of that!), heat will substantially increase chemical activity and deterioration. You have probably heard it a hundred times, but please take it to heart -- store your paper in cool, dry locations. Generally this means places with temperatures below 75 degrees and a relative humidity below 60 percent.

I have one source that suggests that paper life is doubled for every 10 degree F decrease in temperature. (See Archives & Manuscripts: Conservation, a manual on physical care and management, by Mary Lynn Ritzenhaler, Society of American Archivists, 1983)

. Equally amazing is a footnote in the same reference that looks at paper lifespan from the opposite viewpoint. Say that a certificate would last 100 years if stored at 68 degrees F. Its life span would shorten to 25 years if it were stored at 86 degrees F!!

Obviously, you want to avoid moisture. Even a moist atmosphere.  Not just because of what moisture will do to the paper directly, but because of its secondary effects. Those effects include rotting, mildew, and the attraction of insects. Relative humidity of 40% is ideal, 65% is about the top limit.

Foxing is evidence of the growth of mold. It causes cosmetic damage primarily because of an interaction with trace metals found in most paper. Foxing is usually evident as tan or rust-colored stains, reminiscent of the appearance of water staining. Foxing is only minimally reversible, and best avoided by dry storage and good air circulation.

Mildew is a bacterial growth related to the bacteria that causes foxing. It is especially prevalent in damp environments. (Particularly the southeast part of the U.S.) Early evidence of mildew is its distinctive odor.

Hopefully, you keep your paper stored away from insects, rodents and oh yes- the dog. Be very careful, though. Maybe even paranoid. Damage from insects can be very quick. And damage from rodents, even an escaped pet, can be immediate and non-reversible.

In my estimation, the wisest thing you can do is store your certificates singly in polyester holders. Specifically, polyester holders made of Dupont Mylar D™. Most of the better supply dealers carry this type of Mylar. It is not cheap. It is immeasurably cheaper than trying to replace documents.

There are also holders out there made of other plastic materials, including polyvinyl acetate. Whatever you do, avoid vinyl holders. If you have any of these holders I beg you to get rid of them immediately. What makes the vinyl so bad are plasticizers. They are chemicals added to make the vinyl flexible and supple. I have seen many pieces of paper money stored in vinyl for so many years that it appears almost soaked in grease. Don’t let that happen to you.

Polypropylene, triacetate, and polyethylene holders are okay, provided you use archival quality holders. (See links to companies that specialize in archival storage.) 

Thicker holders cost more, but they provide better support for fragile notes. It might be wise to give additional protection to your most valuable pieces.

You should always store your certificates in a flat position. Some people store them in pages in large presentation books. That is okay provided that the pages are guaranteed non-acidic. Do not assume that pages are safe, even in very expensive books.

Until you have the time to thoroughly study paper and paper repairs, it is probably best to avoid ALL repairs. Especially repairs that entail taping pieces of paper together. Glue and tape are extremely detrimental.

Having said that, I will say that there are excellent archival tapes now available that are extremely stable and non-acidic. However, even those should be used sparingly. Any repairs you attempt should be done so someone can reverse them in a few years.

Some conservationists use de-acidification solutions to buffer the effects of acid normally found in paper. Some conservationists are strident in their insistence on stopping acid deterioration before it starts. I agree.

Another way to extend the longevity of your collectibles is to de-acidify them before storage. De-acidifying sprays and solutions are now available for home use. By impregnating the paper with an alkaline reserve, you can neutralize existing acids and inhibit oxidation, future acidity and staining due to certain fungi. However it is best left to the professionals to de-acidify your comic books. De-acidification with proper storage conditions will add centuries to the lifetime of paper.

Perhaps the best known method is the application of  a solution containing an alkaline agent, particularly ethoxy magnesium ethyl carbonate. The most famous solution is sold under the brand name "Wei T'O" and is available in a number of different solutions appropriate for different types of preservation needs. See links to archival storage companies.