Styling guide
How to Clean Old Books: Dust, Musty Smell and Mildew
Most old books can be cleaned at home with a soft brush or an unscented magnetic cloth, working outward from the spine. Musty smells usually respond to airing in a dry room. With active mold, replace the book if you can, or call a conservator if it is valuable. Below: dusting, covers, odors, mold, wet books and storage, step by step.
A note before you start: the methods here are for ordinary books on your shelves. The Northeast Document Conservation Center (NEDCC) notes that cleaning can damage fragile bindings, brittle pages and powdery or flaking leather, and that rare or special books call for a conservator.
What you need
- A soft brush (a clean, soft paintbrush or a makeup brush works)
- Unscented magnetic dusting cloths. NEDCC recommends them over standard cleaning and microfiber cloths, which may contain chemicals that leave residue.
- A vacuum with a soft brush attachment and adjustable suction, ideally HEPA, for heavy dust
- Nitrile gloves and an N95 mask if there's any sign of mold
- A clean, dry work surface away from food and drink
Avoid water, household cleaners, scented dusting sprays and wet wipes. The Library of Congress recommends dusters that don't contain fragrances or other chemicals.
How to dust an old book, step by step
NEDCC's method is simple:
- Hold the book firmly closed so dirt doesn't slip between the pages.
- Clean the top edge (the head) first. It's usually the dirtiest.
- Brush or wipe away from the spine, outward toward the edges, so you don't push dust into the binding.
- Clean the rest of the book the same way: covers, then the other edges.
- Don't rub back and forth, which can damage the pages and cover material.
- Change cloths when they get dirty, and use separate cloths for shelves and books.
All of these steps come from NEDCC's Cleaning Books and Shelves leaflet. NEDCC also notes that magnetic cloths shouldn't be used on books with rough, untrimmed (deckled) edges, heavy soiling or soot; a soft brush or vacuum is better there.
Using a vacuum
For heavy dust or a lot of books: - use a soft brush attachment, - turn the suction down if you can, - hold the book closed and work outward from the spine.
The Library of Congress confirms books can be vacuumed with a small, soft brush attachment if the suction can be reduced.
Cleaning the covers
- Cloth covers: brush gently; don't wet them.
- Paper dust jackets: dust lightly; remove and store flat if torn.
- Leather: dust lightly with a soft brush. If leather is powdery or flaking, stop; NEDCC warns cleaning can damage it.
- Coated or glossy covers: a soft dry cloth is fine.
How to get a musty smell out of old books
Musty odors come from damp storage. The Library of Congress gives several options in its book care FAQ:
- Air and time. Musty odors decrease over time when books are stored with air circulation (not sealed in a box) in a cool place at 35 to 55 percent relative humidity.
- Fan the pages. Stand hardcover books slightly open so the pages fan out for several days. For large or limp books, lay them open with each cover propped so the book isn't lying flat at 180 degrees, and turn to a different section over several days.
- Absorbents. Place the book in a closed container with activated charcoal or baking soda, keeping the book from touching it, for several days. Check often for mold.
- Brief sun, with caution. Short sun exposure can help, but only if fading, discoloration or yellowing is acceptable.
First, make sure the smell isn't from active mold. If you see fuzzy or slimy growth, go to the mold section below.
Mildew and mold
Mold is the one problem to take seriously, both for your health and because it can spread to other books.
Signs: fuzzy or slimy patches (active), powdery spots (dormant), dark stains, a strong earthy smell.
The Library of Congress advises: - take safety precautions such as nitrile gloves and N95 masks, - don't disturb active (fuzzy or slimy) mold, - lower temperature and humidity, and increase air circulation with fans, - if the item isn't replaceable, dry it with a fan blowing out a window, then isolate it in a resealable plastic bag and consult a conservator.
The Library of Congress also notes that treating moldy items can cost more than replacing them, and that if a moldy item is replaceable, replacement should be considered. For decor books, that's usually the sensible choice.
If there are only mold stains (no active growth), the Library of Congress recommends keeping relative humidity between 40 and 65 percent to prevent regrowth and checking the books regularly.
Wet books
If a book gets wet, the Library of Congress advises setting it out to air dry right away. If wet books can't be air dried within two days, they should be frozen until they can be dried, to prevent mold.
Cleaning shelves
Clean shelves are part of clean books: - remove books, top shelf first, - vacuum or dust the shelf, - if you damp-wipe, let the shelf dry completely before putting books back, - keep books off the floor, and change HVAC filters regularly, as the Library of Congress suggests in its cleaning advice.
NEDCC notes that sweeping stirs up dust, so vacuuming and dust mops are preferable for floors near bookshelves.
How to care for old books on display
Prevention beats cleaning. The Library of Congress recommends: - cool and dry: 70 degrees Fahrenheit or below, at 30 to 55 percent relative humidity, - no extreme swings: keep books away from vents and radiators, - no attics, basements or garages, - minimal light: no direct or intense light, - upright, not leaning, with bookends, and oversized books laid flat, - regular dusting, because dust attracts pests and absorbs moisture that can lead to mold.
Light damage is cumulative, so rotate books on sunny shelves (Library of Congress).
For styling tips that keep books healthy, see decorating with old books and how to decorate bookshelves with books.
Quick troubleshooting
| Problem | What to do |
|---|---|
| Light dust | Magnetic cloth or soft brush, outward from spine |
| Heavy dust | Vacuum with soft brush, low suction |
| Musty smell, no mold | Air out, fan pages, charcoal or baking soda container |
| Fuzzy or slimy growth | Don't disturb; gloves and mask; replace if possible |
| Old mold stains | Keep humidity 40-65%, monitor |
| Wet book | Air dry immediately; freeze if not dry within two days |
| Flaking leather | Stop; consult a conservator |
Decor books ready to shelve
If you're buying books for decor, start with books that are already in good shape. Our lots are real hardcover books. Good used condition: clean and intact, with light shelf wear possible. For a collected, aged feel, see the 2-foot Vintage-Look Shelf Collection, or browse rich library tones like Autumn Oak and light ones like Dunes in our decorative books shop.
Frequently asked questions
How do you clean old books without damaging them?
Hold the book closed, clean the top edge first, and brush or wipe gently outward from the spine with a soft brush or unscented magnetic cloth. Don't rub back and forth, and don't use water or household cleaners.
How do you get a musty smell out of old books?
The Library of Congress suggests storing them with air circulation in a cool space at 35 to 55 percent relative humidity, standing hardcovers slightly open so pages fan out, or placing the book in a closed container with activated charcoal or baking soda that doesn't touch the book.
What should I do if an old book has mold?
If mold is fuzzy or slimy, it's active: don't disturb it. Use gloves and an N95 mask, lower humidity, and consider replacing the book if it's replaceable. Consult a conservator for valuable books.
Can I use a vacuum to clean books?
Yes, with a small soft brush attachment and reduced suction. The Northeast Document Conservation Center recommends a HEPA vacuum for heavy dust.
How often should I dust my books?
It depends on how fast dust builds up where they're kept. Regular dusting helps prevent pests and mold, since dust absorbs moisture.
