A Delicate Touch: Preserving Rare Books, Prints, Letters and Other Objects on Paper at the NLM

The National Library of Medicine will join libraries and institutions nationwide to celebrate the second annual Preservation Week (April 24-30), promoting ways to preserve belongings whether in a library, museum, or home. To highlight NLM’s 2011 Preservation Week activities, we have a behind the scenes look at how the Library preserves its valuable collection of books and other paper items, plus a few tips on what you can do at home.

While the National Library of Medicine is known for its innovative online resources and expertise in health information technology, the Library also houses one of the world’s preeminent collections of historical and rare medical and scientific books, manuscripts, letters and prints.

For example, it owns an 11th century Arabic medical manuscript, “The Comprehensive Book on Medicine” (Kitab al-Hawi fi al-tibb), a first edition of Charles Darwin’s “On the Origin of Species” and some of the greatest anatomical, zoological and botanical books published in the last 400 years.

The Library also houses the letters of American Red Cross founder Clara Barton, prints by Albrecht Dürer, and William Blake, and the papers of scientific pioneers, including Nobel Prize winner Marshall Nirenberg, who deciphered the genetic code.

NLM conservators lean over a old map

Before making possible repairs, Holly Herro and Kristi Davenport examine an April 1875 map of Manhattan showing the locations of smallpox victims.

These remarkable items are just a few examples of what can be found in this unique collection. Fortunately, NLM has trained conservation staff  who use appropriate enclosures and storage conditions to protect these artifacts from the damaging effects of improper lighting, airborne pollutants, insect infestation and mold.

Holly Herro is the conservation librarian for the History of Medicine Division, where she coordinates many of the Library’s conservation efforts along with associate conservator Kristi Davenport.  Herro has 22 years of experience in conservation. Her resume includes restoring George Washington’s plantation records and Thomas Jefferson’s letters.

She chose a career in librarianship because her father discouraged her from pursuing an art degree in college. “I had to follow my artistic interest somehow and decided to work on repairing books,” she said.

How do the NLM conservators know what to work on? Here’s the usual process. When a staff member notices a book in need of repair, it is flagged and a form is filled out, describing the nature of the damage. The book is then sent to the NLM conservation lab for repair, stabilization or rehousing.  “Rehousing” means storing a book in a protective enclosure—a non-damaging (e.g. acid-free and lignin-free) box, envelope, polyester sleeve or folder.

Currently, Herro and Davenport are working with NLM staff on a major library initiative to digitize important medical heritage books published prior to 1875. “When a book is chosen for digitization, we make sure that it’s in good condition prior to scanning,” Herro explains.

Davenport has worked in a book and paper laboratory for seven years, first at the University of South Carolina and now at NLM. She joined the field because she’s always been drawn to historic materials, and spent many of her teenage years volunteering in libraries in her hometown of Orlando, Florida.

Much of her work involves repairing book bindings, mending tears in manuscripts and prints, and removing harmful tapes—such as pressure-sensitive tape—from paper ranging from 20th century lab notes to documents from earlier centuries. She recently removed some gummed linen tape which attached Dürer’s famous print, “Melencolia” to a mat. “It took some time to get the job done, but it’s great to know that the print is now safe,” Wright says.

If you’d like to learn how to protect and preserve your personal and family treasures, here’s advice from the NLM experts:


  • Digitize, microfilm or even photocopy important papers and treasured paper memorabilia. Store originals and copies in separate locations.
  • Store books and papers in a dry environment with moderate temperatures that do not fluctuate widely.
  • Don’t store books and papers in the attic or the basement, where conditions can vary widely and reach extremes. Avoid high humidity and risk of damage from flooding.
  • Store books on sealed bookshelves. Books stored on open shelves, which abut an exterior wall, can be affected by fluctuating exterior temperatures. Unsealed wood gives off acidic vapors which are harmful to materials made that contain cellulose. You can create a seal or barrier by lining shelves with acid-free board or inert polyester film. Make sure books are upright (vertical) on shelves, grouped according to size. Oversized or thick, heavy books should be shelved flat (horizontally).
  • Consider placing cherished books and papers in acid-free, lignin-free boxes. Individual papers can be stored in inert polyester sleeves or acid-free folders before boxing. All supplies can easily be purchased online from library vendors who specialize in selling archival products. When in doubt about which supply to order or how to store an object correctly, consult a conservator.
  • Keep books and other papers out of direct sunlight. Closed drapes can be used to reduce the sunlight levels.

If you need more specialized help, consider hiring a conservator. Information from the American Institute for Conservation of Historic and Artistic Works is a good first step.

By Judy Folkenberg, NLM staff writer.