How Do You Clean World's Oldest Maps?

The tables in the basement of the Municipal Archives are covered with household staples: cotton swabs, tweezers, food strainers, measuring cups, ashtrays and other materials.

None are items that one would expect to find in a professional art conservation laboratory. But they are tools used by a group of government workers who wash and care for some of the oldest existing maps and architectural drawings of New York City. They call themselves “dry cleaners.”