Ancient manuscripts connect us to our distant past. Without them, we wouldn’t be able to understand our histories, traditions, and knowledge gleaned from many lifetimes of experience. But there’s a big problem: paper and parchment aren’t known for longevity. The reason we can read about the plays of ancient Greeks, understand the wisdom of Eastern philosophies, or even glimpse the yellowing founding documents of entire nations is thanks to legions of archivists throughout history who’ve meticulously restored, protected, and preserved these old (and prone to crumbling) manuscripts for future generations.

Throughout the Middle Ages, scriptoria around the world served as repositories of human knowledge, and in Yerevan, Armenia, the museum and research institute known as the Matenadaran continues that tradition.

Visit the Matenadaran today and you’re greeted by a grand, fortress-like building constructed from gray basalt stone. At the building’s entrance is a large statue of Mesrop Mashtots, a medieval Armenian linguist who’s credited with developing the Armenian alphabet. This imposing structure denotes the importance of the delicate treasures found inside—23,000 manuscripts, with some dating back 1,500 years. Although the Matenadaran is home to the largest collection of Armenian manuscripts in the world, it also houses ancient texts from other civilizations throughout history.

“Matenadaran means the ‘repository of manuscripts,’” Vahe Torosyan, a scientist secretary at the Matenadaran, tells Popular Mechanics. “However, the Matenadaran is not only a storehouse of manuscripts but a research institute and a museum where manuscripts are stored, cared for, restored, studied scientifically, and displayed.”

Restoring these manuscripts requires an intense level of artistry and dedication. Before restorers can even begin repairing battered manuscripts, they first need to clean the surfaces of pages and miniatures (the small illustrations that often accompany medieval texts). This means removing any dust, candle wax, insects, dirt, stains and more that might’ve adhered to the brittle pages over the centuries. Paper and pigments are also examined under a microscope to make sure that paint layers are solid before cleaning can begin.

Restorers then use a special, handmade Japanese paper created from the bark of mulberry trees to repair the pages, whether a small tear or a gaping rip. Using this specialized paper—in various thicknesses and shades—restorers can create a seamless transition between the original document and the restored parts.

“Japanese paper is a unique material and has a special structure,” Gayane Eliazyan, head of the department of restoration, tells Popular Mechanics. “The edges of the paper have long fibers that are easy to connect with the original paper, and the passage from the original manuscript material to the Japanese paper occurs very smoothly.”

Although preserving ancient texts is a centuries-old profession, 21st century technology provides the ultimate protection for these fragile objects. When a document contains undertext, which is writing that’s been replaced by existing text, the Matenadaran uses multi-spectral imaging to capture the manuscript in 28 distinct frames—each frame representing a range of the visual spectrum as well as UV and infrared light. These various light spectra can capture the hidden words hidden beneath the work.

With these digital recreations along with digital scans of other manuscripts, physical texts never leave the safety of the Matenadaran itself.

Preserving this book block is only one part of the restoration process; the restorers also bring that same level of exacting attention to mending a manuscript’s binding, leather cover, and endband (the woven decorative parts found at the upper and lower edges of the book’s spine).

Eliazyan says that the restoration department of the Matenadaran also has a biological laboratory, and like many laboratories around the world, it faces funding challenges. The department needs new equipment to keep up with new restoration techniques.

As Armenian universities still do not have educational programs for certifying restorers, the Matenadaran serves as a teaching center and school for this specialization. Eliazyan hopes that continued support from grantors or the Armenian government will help train the next generations of specialists eager to be keepers of the heritage of human knowledge—past and present.

Darren lives in Portland, has a cat, and writes/edits about sci-fi and how our world works. You can find his previous stuff at Gizmodo and Paste if you look hard enough.