The National Gallery of Art knows a thing or two about preservation. In addition to the many works on view in its public galleries, countless others are tucked away at its conservation division in Landover. Since the hardcore historians and restorers work in relative isolation in order to best protect the art, we peons don’t get to see the pieces until they’re in proper condition. But for those curious about the conservation progress, the NGA is mounting a new show drawn from the book collection of noted conservation scientist Robert L. Feller. In addition to his volumes exploring the science of color and history of paint, visitors can see Feller’s journals from his 1966 trip to Florence, Italy, where he worked with conservators responding to the city’s flood. Aspiring and amateur art historians will enjoy this peek into the world of one of the field’s great masters. The exhibition is on view Mondays through Saturdays 10 a.m. to 5 p.m. and Sundays 11 a.m. to 6 p.m. at the National Gallery of Art, 6th Street and Constitution Avenue NW. Free. (202) 737-4215. nga.gov.