by William M. Cole P. E.
Mold & Mildew Summary
Treatment of Mold
Game collecting today is for both fun and profit. Yet, the
item you thought was going to increase in value year after year has suddenly
turned yellow after only three months and is now worthless. What happened?
What could have been done to prevent the yellowing? This article will discuss
what materials are best suited for long term storage and the guidelines
for proper preservation.
According to the US Library of Congress, the preferred material for preserving
valuable documents is uncoated archival quality polyester film, such as
Mylar® type D or equivalent material such as Melinex® 516. Mylar® is an
exceptionally strong transparent film that resists moisture, pollutants,
oils and acids. With a life expectancy of hundreds of years, Mylar® will
outlast most other plastics. In addition, the brilliance and clarity of
Mylar® enhances the appearance of any paper collectible. (Mylar® is a registered
trademark of DuPont Teijin films. Their brands of archival quality polyester
films are Mylar® type D and Melinex® 516 of which they are exclusive manufacturers).
POLYETHYLENE AND POLYPROPYLENE
For years collectors have
stored their movie posters, comic books, baseball cards and other collectibles
in polyethylene bags, PVC sheets and plastic wraps. Although such products
may be useful in keeping away dirt, grease and vermin, many plastic sleeves
contain plasticizers and other additives which can migrate into paper and
cause premature aging. Both polyethylene and polypropylene contain solvents
and additives in their manufacture to assure clarity and increase the flexibility
in the plastic. Polyethylene when uncoated without any solvents is a good
moisture barrier but has a high gas transmission rate, and eventually shrinks
and loses its shape under warmer conditions.
In recent years polypropylene bags have been sold under the guise of
being archivally sound. This is far from the truth. Only uncoated and untreated
material is suitable for archival protection. Currently, the only way to
seal polypropylene is to add a substance called PVDC (Polyvinyl Dichloride
which is a relative of PVC) to allow the material to be heat sealed. Therefore,
once you add the harmful additive, the sleeve now becomes non archival and
should not be used for long term storage.
ACID FREE BOARDS AND BOXES
Because ordinary cardboard is
itself acidic, storage in cardboard boxes may be hazardous to your collection,
and is a leading cause of premature deterioration of comic collections.
For proper storage, only acid free boards that meet the US Government's
MINIMUM requirements are acceptable. These requirements have been defined
as boards having a 3% calcium carbonate buffer throughout and a minimum
pH of 8.5. Anything less will hasten your collection's destruction. While
many advertisers claim that their boards are "acid free at time of
manufacture," they are in reality only spray coated with an alkaline
substance making them acid free for only a very short time. Boards termed "acid
free at time of manufacture" do not offer sufficient protection or
storage for anything other than short term. True acid free boards have been
impregnated with a calcium buffer resulting in an acid free, alkaline pH
content of 8.5 throughout.
Another way to extend the longevity
of your collectibles is to deacidify them before storage. Deacidifying 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 deacidify your collectibles. Deacidification
with proper storage conditions will add centuries to the lifetime of paper.
In summary, we recommend the following guidelines for the maximum protection
of your collectibles: Deacidify the paper; store in Mylar® sleeves with
acid free boards and cartons; and keep the collection cool, dry and dark.
Periodic inspections and pH and humidity tests are also recommended. By
following these simple guidelines you can be assured of a collection that
not only will increase in value, but will also last for many years to come.
Bill Cole Enterprises, manufacturer of archival materials:
... or visit your local comic & game dealer.