I’m Kaila, and over the years, I’ve gathered a lot of experience in caring for books. Today, I want to share some tips on book mold
What is Book Mold VS Foxing?
Why do books mold?
Books are made from plant fibers, containing nutrients like starch and cellulose, similar to wood. These materials create a perfect environment for mold, especially in damp, enclosed spaces. Mold needs two main things to grow: the right temperature and moisture. Once these are present, mold can quickly appear.
Since books are mostly made of cellulose, they can easily absorb moisture. Once damp, mold can start growing on the surface, leaving visible stains. Luckily, keeping books dry isn’t too hard. Regularly flipping through pages, airing them out, and storing them in a well-ventilated area can help prevent mold.
how common is book mold?
I used to wonder why books seemed to mold so easily until I looked into it. There are a few main reasons:
- High Humidity: When books are stored in damp areas like basements or near bathrooms, moisture gets trapped in the pages. This environment is ideal for mold, especially if humidity levels are above 60%. The fibers and starch in the paper are exactly what mold needs to thrive.
- Poor Air Circulation: If a bookshelf is rarely opened or books are packed too tightly, there’s no airflow, and fresh air or sunlight can’t reach them. This closed-off, damp space allows mold to grow freely. Mold spores can then spread throughout the bookshelf and onto other books.
- Temperature: Temperature also plays a big role. Mold grows faster in warmer conditions, which is why books tend to mold more during the summer or in hot regions. But be careful with sunlight, as too much exposure can age and weaken the paper, making it more susceptible to mold.
How Do I Prevent Mold on Books?
So what do I usually do? Regularly inspecting, airing out, and flipping through books are some of the simplest ways to prevent mold. If your home is especially humid, consider using a dehumidifier to control moisture levels—this can really help slow down mold growth.
I also make sure to open up my bookshelves now and then to let air circulate. In humid seasons, this is particularly effective. Keeping airflow steady and storing books in a dry area are key to protecting them from mold.
what does mold on books look like?
Book Mold examples：
Is book mold dangerous? Can book mold spread?
Yes, book mold can be harmful, especially for people with respiratory issues, allergies, or weak immune systems. Mold releases tiny spores into the air, which can trigger allergic reactions, asthma, or other breathing problems when inhaled. Just handling moldy books can cause skin irritation or make allergies worse.
Mold also damages books by weakening the paper and causing stains, which can ruin valuable or treasured books over time.
Here are some simple tips for dealing with moldy books safely:
- Wear protection: Use gloves, a mask, and, if possible, protective glasses to avoid contact with mold spores.
- Clean in a ventilated area: Try to work outside or in a room with fresh air.
- Gently clean surface mold: Use a soft brush or cloth to carefully wipe off any visible mold. Go slowly to avoid spreading mold spores around.
- Freeze badly affected books: Freezing moldy books stops the mold from growing. This is a good option for valuable books that might need professional cleaning.
The main type of mold that grows on books is Aspergillus niger, or black mold. This mold can seriously damage books by affecting their appearance, weakening the paper, and making the pages brittle. Over time, this not only makes the books look worse but also reduces their usability and lifespan.
Book Moisture-Proofing “Tools”
- Resealable Bags Using resealable bags is a simple way to protect books from moisture and dirt. They’re inexpensive and effective, but it can be time-consuming to seal each book individually—especially if you have a large collection.
- Plastic Film For books stored on open shelves, covering the shelf with a layer of plastic film can help minimize contact with humid air. This keeps moisture away from the books without sealing each one.
- Desiccants and Bamboo Charcoal Packs In closed bookshelves, placing bamboo charcoal packs or desiccants next to your books can absorb excess moisture from the air. Just remember to replace them regularly to keep them effective.
- Dehumidifier A dehumidifier is especially helpful during rainy or humid weather. Running it near your bookshelves can significantly reduce moisture in the air and help prevent mold growth.
how to get rid of book mold?
Tips for Preventing Mold on Books
- Reduce Exposure to Humid Air
Keeping books away from humid air is essential. To reduce moisture, avoid leaving windows open near bookshelves. If your books are stored in a cabinet, keep the doors closed tightly and avoid opening them frequently. - Position Bookshelves Away from Damp Walls
Place bookshelves away from outer walls, kitchen and bathroom walls, or walls with water pipes, as these are more prone to dampness and leaks. Even if they don’t look wet, these walls can still carry moisture, which could harm your books over time. - Avoid Storing Books Right Up to the Ceiling
Water leaks from the ceiling, especially in top-floor rooms, can be unpredictable and hard to detect. If you live on the top floor, keep some space between the top of the shelf and the ceiling, so you can spot any leaks early and handle them before they cause damage. - DIY Anti-Mold Paper
You can make anti-mold paper by dissolving a small amount of camphor and borneol in 80% alcohol. Soak absorbent paper in the solution for 2–3 minutes, then let it air dry. Placing this paper between book pages helps prevent mold and pests. - Alum Solution for Mold Prevention
Using a cotton pad dipped in an alum solution, gently wipe it across book pages to dehydrate and kill mold spores. You can also mix alum into any adhesive when repairing books, as this provides excellent mold protection.
Tips for Handling Moldy or Damp Books
- Avoid Quick Drying
Mold on books is usually caused by moisture, so drying them too quickly (like with heat) can cause pages to wrinkle. Take the book out and inspect it to ensure it’s dry. If it feels damp, place it in a ventilated area and let it air dry naturally. - For Small Mold Spots
Gently wipe off mold spots with a dry cloth or towel as much as possible. Then, dip a towel in soapy water or mild detergent, wring it out well, and use it to wipe any remaining mold spots. Follow up with a clean, slightly damp cloth to remove any soap residue. Be careful not to soak the pages. - For Large Moldy Areas
For larger mold stains, use alcohol. Fully moisten the pages with alcohol (which will evaporate without leaving moisture) and press the pages between a gypsum board or ceramic tile to keep them flat. This method dries quickly, eliminates musty smells, and helps prevent future mold growth or pests. - Drying in a Ventilated Area
Let books dry in a well-ventilated space, being careful with thick books to prevent pages from sticking together. You can use a fan to speed up the process, but be gentle. To keep pages from sticking, sprinkle a bit of cornstarch between them, then shake it off when dry. Occasionally flip through the pages to separate them as they dry. - Preventing Future Mold
The best way to prevent mold is to avoid storing books in damp areas. Basic book preservation includes keeping them in a dry, low-humidity environment.
Why Freezing Damp Paper Helps Restore It
Placing damp pages in the refrigerator or freezer can almost restore them to their original state. How does this work? Here’s the science:
According to Professor Ren Hao from Jinan University, paper is made up of plant fibers, fillers, and binders, which contain hydrophilic hydroxyl groups. When paper gets wet, water molecules enter the fibers, causing them to swell, dissolve slightly, and deform. The different lengths of fibers in the paper dry at different rates, leading to wrinkles when air-dried.
Freezing slows down the evaporation process, allowing water to leave the fibers gradually. This gives the fibers more time to relax and return to their original shape. Professor Ren recommends blotting off surface water with a towel or tissue, then pressing the damp paper between two hard surfaces, like wooden boards or books, before placing it in the fridge to minimize wrinkling.
