What's Your Damage? How to Identify Problems in Archival Collections

Archival collections face all kinds of threats, from mold and bugs to acidic ink and overzealous researchers. Learning how to recognize damage before it spreads is one of the most important skills you can develop when caring for a collection. While not every issue calls for professional conservation, understanding what you’re looking at can help you make better decisions about triage, treatment, and preservation. This blog breaks down common types of damage you’ll encounter and what to do when you spot them.

Mechanical Damage and Wear

The most obvious type of damage is mechanical. Time, gravity, and repeated handling cause materials to bend, curl, roll, or tear. This includes photographs that have shriveled into tight curls as their emulsion shrinks or paper that has softened and warped from being under-filled in a box. These materials simply aren’t supported well. Using padded folders, proper housing, and fully filled boxes can keep fibers intact and prevent structural breakdown.

Repeated handling is another culprit. You don’t need to wear gloves for everything. Clean, dry hands are fine for paper, but photographs, textiles, and furniture call for gloves. Avoid freshly applied lotion and nail polish, both of which can transfer to materials. And, please, stop people from licking their fingers to turn pages. Yes, that still happens. Saliva can break down organic materials and even invite mold.

Acidity, Red Rot, and the Danger of Ink

Paper and ink are often inherently acidic, and over time they’ll eat themselves alive. Iron gall ink is notorious for this. You might notice holes where ink once sat or yellow ghosts where newspapers or paperbacks used to be. That’s a clear sign of acidification.

You can slow this process by using acid-free, lignin-free, or buffered storage materials. Buffered folders contain chalk to help neutralize acidic conditions. Red rot in leather-bound books is another tell-tale sign of acidification. If you touch a book and come away with red powder on your hand, that’s red rot, and you’ll want to box that item before it disintegrates any further.

Fading, Toning, and Foxing

Fading and discoloration from light and heat are common. Inks and thermal reproduction processes like old photocopies or receipts can disappear entirely if stored in unstable environments. If something is actively fading, make a scan or a stable photocopy now. You may not get another chance.

Toning is the yellow or brown hue that spreads across acidic paper. Foxing, by contrast, shows up as rust-colored spots or blemishes. It’s not always active mold but may signal past moisture issues. These speckled stains are especially common in older books with high cotton content.

Mold, Mildew, and Pests

This is where things go from "keep an eye on it" to "act immediately." Mold is fast and aggressive. It needs moisture, warmth, and something to eat. Paper, leather, adhesives, and dirt all qualify. Mold comes in many varieties and appearances, but the smell is usually your first clue. If you suspect mold, put on a respirator and gloves, and isolate the item. Dead mold can still reactivate in the right conditions, so you must clean anything it touched.

Pests can include insects like moths, beetles, and silverfish, as well as rodents. Even if bugs don’t directly damage paper, their presence signals environmental problems like humidity. Droppings, eggs, and frass (insect debris) are all signs to watch for. If you see any of these, start a quarantine immediately and check your climate control.

Water Damage

Standing water is never just standing water. If items get wet, the water itself might be damaging, but the mold that follows is worse. Water-damaged collections must be dried quickly and carefully, ideally in a freeze-drying chamber designed for archival materials. Freezing stops mold growth and buys you time to plan recovery.

Vinyl records or plastic-heavy materials may survive a flood better than paper, but water still compromises sleeves, labels, and housing. Even dampness from a leak can cause problems if not caught fast.

Disaster Recovery: When to Call in Help

If your archive has suffered serious damage from water, mold, or pests, you don’t need to go it alone. There are professional disaster recovery companies that specialize in archives and museums. Polygon is one well-known provider, and the Society of American Archivists (SAA) maintains a vendor list.

In major recovery situations, prioritize items that are unique, heavily used, or of the greatest value to your institution. Make sure staff safety always comes first. No collection is worth risking someone’s health. If necessary, outsource the response to trained professionals with the right tools, PPE, and equipment.

Building a Culture of Prevention

Most of the time, prevention is cheaper and easier than recovery. Invest in good housing and environmental controls now. Track and regulate temperature and relative humidity, ideally keeping RH between 30 and 50 percent. If your collections live in a region that’s getting stickier, you’re not imagining it. Climate changes mean archives in more northern or historically dry areas may now be dealing with humidity-related problems for the first time.

Digitize frequently handled materials to reduce wear, and build a disaster recovery buffer into your budget so you’re not scrambling for funding when things go wrong. That could be as simple as setting aside funds for new boxes or as complex as maintaining a relationship with a conservation vendor for future emergencies.

Use Your Networks and Make a Plan

Other people have dealt with this before. Reach out to your regional museum association, your local colleagues, or a national listserv. Tap into the wealth of experience in your community and the profession. Share your own lessons learned, and ask for help when you need it.

Finally, don’t wait for a disaster to make a plan. Resources like dPlan.org can help you draft and update a written disaster plan. Review it annually, and make sure new staff are trained. Identify evacuation procedures, backup contacts, and the materials you’d prioritize for rescue.

You won’t stop every disaster, but you can be ready to respond.