Protecting Collectibles from Mold and Humidity
By Mary Haberstroh
For collectors of paper, wood, fabric, and leather items, mold and mildew are a major concern when it comes to preserving and conserving a collection. Sports cards, stamps, postcards, ephemera, and books are all susceptible to mold if stored improperly. Mold is a growth caused by fungi that appears fuzzy in texture. Mildew is a type of mold that emits a strong smell. Mold and mildew are dangerous to paper and other natural fibers because they stain and consume the paper and leave it in very poor condition. Molds grow when humidity in the atmosphere reaches above 60% in damp, warm, dark, poorly ventilated areas like attics and cellars. These places are the worst for collectibles to be stored because they not only invite mold and mildew, but also destruction by insects that feed on paper and other fibers. Some people toss anything of value such as sports cards, stamps, postcards, ephemera, and books in the attic without giving a second thought as to the potential damage that can occur to these items. When the time comes to clean out the cellar or attic and these items are discovered to bear mold and the owner wants to dispose of them at a garage sale or sell them to a dealer, these items will not fetch the prices they would have had they been better preserved over the years.
Another condition that can affect paper, and especially books, in improperly stored conditions is foxing. Foxing occurs when rust colored spots appear on paper - it is a dormant fungus. Foxing frequently appears in books and ephemera made in the eighteenth and nineteenth centuries because the paper used had very thin fibers. Paper collectibles that have foxing on them should be left as they are and stored in archival storage folders or polyethylene covers.
Collectible items that bear mold can trigger allergies and asthma, making it unhealthy for the collector to keep such items exposed to the atmosphere. There are archival storage products that can keep mold from expanding in a paper item and prevent allergies from being triggered. Collectibles should be placed in these special protective products only after any fuzzy mold has been removed, if possible, from the paper or fabric item.
There are ways to combat the further growth of mold and also prevent collectibles from growing mold that are inexpensive and will help preserve the objects in a collection. The easiest ways to remove a small amount of mildew from a book cover are by vacuum or a dry cloth. With the vacuum method, use the long, slender crevice tool and attach it to the hose. Use the lowest force of suction to remove the mold from the book cover. Make sure the book cover is dry before vacuuming. The mildew will be scooped up by the vacuum cleaner. With the dry cloth method, gently wipe the mildew off the cover. This is best done outside so the mildew does not enter the air indoors and settle elsewhere. The dry cloth method can also be used on postcards or sports cards to remove visible mold, but the vacuum method is not recommended for paper because it may tear paper or curve the edges. Thin paper that is much older should not be rubbed as the paper may tear, but should be placed in a polyethylene bag which will prevent the mold from spreading to other items it may come in contact with.
Books and paper collectibles treated with fungicides can even be more susceptible to mold after being treated. In the past, some museum preservationists have used bleach and other chemicals to remove mold but more often than not the paper items exposed to these substances were damaged. One popular chemical used was Thymol and it was not just ineffective in controlling mold, but it is also turned out to be a carcinogen. Paper collectibles should not be treated with chemicals at all if they are to be preserved as best as possible.
To keep a collection such as stamps, postcards, sports cards, books, and ephemera free from mold, store the items in a room of the house that is both air conditioned with a relative humidity level between 35 and 50%. The ideal room temperature is from the mid to upper 60's, or slightly below average room temperature. Good air circulation is very important for collectibles to remain in the best condition possible. A dehumidifier can help combat the growth of mold and mildew in a collection. Collection items should be kept in acid free storage holders, and there are holders to fit all sizes of paper collectibles. Ephemera such as letters and magazine advertisements can be contained in polyethylene sleeves that can be held in a binder.
The best way to preserve an item already damaged by some mold is to immediately transfer it to a dry area which will retard the further growth of mold. Paper collectibles and books with mold on them should never be left outside in the sun to dry out. Direct sunlight can discolor the paper plus the ink colors used for printed pieces of paper. If possible, remove the mold using either the vacuum or dry cloth method. Once the growth of mold stops, the collectibles can be placed in their proper storage inserts.
A few suggestions for new collectors of paper collectibles:
Seek out only items that are in top condition for the collection. If a desirable item is encountered but has mold on it, simply make a note of the item, any years, names, and titles that will help identify it, and start the hunt for a better quality copy suitable for your collection.
Try to avoid accumulating more paper items than you can properly care for. Consider pursuing quality over quantity, and consider focusing your collecting interests. Highly specialized collections such as Baltimore Orioles 1898 sports cards, postcards of Japanese geisha from the 1930's, or Qajar Iran stamps from 1855, are just some fun examples of areas that would be challenging to pursue, fascinating to own, and worthy of the time and expense to properly store and display.
About the Author:
Freelance writer of Tucson, Arizona Mary Haberstroh is a frequent contributor to Hobbizine. She is an avid collector of many things including theater programs and millefiori paperweights. She can be reached at: firstname.lastname@example.org