Promoting passion in book collecting

Banish Mold and Mildew from Your Personal Library


Recently a follower posted a question about mold removal on our Facebook page. It’s certainly a timely topic, given that we’ve entered the hot, rainy season. These pernicious fungi can wreak havoc on your personal library, causing deterioration, discoloration, and even health problems. If you encounter mold or mildew in your collection, it’s important to act immediately.

Identifying Mold and Mildew in Rare Books

We’ve all seen fuzz on leftovers that were pushed to the back of the fridge, or smelled that musty odor in the basement. But mold and mildew can take on a variety of forms. Mold might look like a fine fuzz, or it could resemble the filaments of a spider web. Mold may also cause unusual stains and spots on your book’s pages. Mildew, on the other hand, can cause a powdery, flaky layer on the surfaces of your books. It can also appear in patches or spots.

Though mold and mildew are different kinds of fungi, they thrive in similar conditions. Both live off organic material, like leather, wood, cloth, and paper. They also prefer warm, humid places with little air movement. And they both spread easily, by emitting clouds of spores. That’s why you should isolate any books or ephemera that show signs of mold or mildew infestation.

Removing Mold and Mildew from Your Books

Before you attempt any cleaning methods, ensure that your book is completely dry. Attempting to clean a damp or wet book usually just results in smearing the mold or mildew and pushing it further into the surface. Once your book is completely dry, use the appropriate method to eliminate mold and mildew.

  • To treat a cloth, leather, or other hardback book, you can spot clean the affected areas with denatured alcohol. Use a soft cloth or brush to apply. Be sure to test a small area first, to check for possible discoloration or damage.
  • On paperback covers, dampen a soft cloth with denatured alcohol or hydrogen peroxide. Brush away the mold or mildew gently and dab any excess liquid. Make sure to dry the book thoroughly before returning it to your shelf.
  • To remove fungus from an individual page, place a piece of wax paper underneath it, to protect the page below. Use a soft cloth or brush dampened with hydrogen peroxide or denatured alcohol to gently treat the affected areas. Again, be sure to dry the pages thoroughly before closing the book and putting it back into your library.
  • As an alternative, you can also use a HEPA filter vacuum hose with a thin cloth or dryer sheet placed over the nozzle. Brush the areas gently to remove the mold or mildew.
  • If you can’t treat your book right away, place it in a plastic zip-top bag and put it in the freezer. The cold will halt new growth, though it won’t necessarily kill all the spores.

If you feel uncomfortable doing the treatment yourself, or if the damage is quite extensive, it’s usually best to consult a qualified conservator. In some cases, the cost of treating a book may exceed its value, and a conservator can give you advice on how to proceed.

Prevention Is the Best Medicine

The best treatment for mold and mildew in your library is to prevent them from growing in the first place. These fungi grow in very specific conditions, so controlling the climate of your library can significantly reduce the probability of an infestation.

  • Keep your books in a climate controlled area, ideally with a temperature around 70 degrees Fahrenheit. Use the air conditioner in the summer and turn on the heat in the winter to maintain a consistent temperature.
  • If you live in a humid climate, employ a dehumidifier to keep your library’s humidity under 60 percent. Also refrain from placing your books against the outside walls of your home.
  • Still air promotes mold growth, so place your books in a location with proper air circulation. Some collectors also direct a fan toward their volumes, but this can dry books out over time, making them brittle and fragile.
  • Clean surfaces are less habitable for spores, so dust the exposed surfaces of your books on a regular basis. Use a dry, soft cloth or brush to remove dirt and debris.
  • The moist, dark environment of potting soil is an ideal place for mold and mildew to grow. Thus it’s best to keep live plants out of your personal library.
  • Lavender essential oil is a natural anti-fungal and was once a popular means to prevent the spread of mold and mildew; collectors would place it directly on bookshelves. But it also scents your books and causes discoloration, so this technique is best avoided.

Have a question about caring for your rare and antiquarian books? Post it here, send us an email, or share it on our Facebook page!

One comment on “Banish Mold and Mildew from Your Personal Library

  1. This is known as house cooking and not only does
    it not remove mold, it fosters its growth. You will need to mix a
    cup of it in a gallon of water and then scrub the affected area
    two or three times until all the traces of mold have been removed.
    This is a very interesting question that everyone would like to

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This entry was posted on July 24, 2013 by in Caring for Rare Books and tagged , , , .
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