What's happening behind the scenes at your favorite Chicago museum?

Inside the Chicago History Museum's library

Mannequins in the Chicago History Museum's costume and textile collection

House slippers that were once owned by Abraham Lincoln

Various articles that were used during Abraham Lincoln's time in the White House

A drinking water container and commode found in a Chicago fallout shelter

Copies of a Chicago city directory from 1913

A Bes-Ben hat made by Benjamin Green-Field

A Bes-Ben hat made by Benjamin Green-Field

Rolled blueprints and schematics within the Chicago History Museum archives

An item that melted during the Chicago Fire of 1871

Before any item in the Field Museum’s collection of more than 30 million objects and specimens makes it into an exhibition, it passes through one of three conservation labs, where staff members assess its condition, stabilize any damage and prepare it for display. Leading up to the museum’s upcoming exhibit “Ancient Mediterranean Cultures in Contact”—which explores the interaction between Roman, Egyptian, Greek and Etruscan cultures—conservator Debbie Linn puts artifacts that are hundreds of years old under a microscope—literally.

“We are displaying less than 1 percent of our objects overall, so whenever we can pull something out of storage and use it, it’s really exciting,” says Linn. One such seldom-seen item in the upcoming exhibit is a glass pitcher that survived the volcanic eruption in Pompeii in 79 A.D. Though some of the object’s beautiful iridescent coating is chipping away, conservators prioritize stability over cosmetic restoration. “We don’t want these items to look brand-new,” says Linn. “We want them to look like they’ve had use, like they’ve had a life.”

Once a piece is cleared for display, it’s sent to the Field Museum’s mount shop, where a team constructs an apparatus to hold it while it’s exhibited. “The better job you do, the less your job is apparent,” says exhibit preparator Kate Ulschmid, pointing out that the team’s metalworking, sewing and painting are intended to blend into the background.

After being mounted, nearly every item in an exhibit needs a case or a stand. Luckily, the Field Museum houses its own woodshop, which fabricates a variety of custom fixtures. Located on the fourth floor of the building in a somewhat-narrow hallway, the department usually produces large items in sections so they can be squeezed into a small freight elevator and reassembled in an exhibit. In many ways, these cases are the most important part of any show, if only because they keep visitors’ hands off the priceless relics.

Conservator Debbie Linn examines a gold and glass necklace dating back to the 4th century A.D.

A mummy headpiece dating back to the 6th to 3rd century B.C. in the Field Museum's conservation lab

A variety of objects being prepared for display in the Field Museum's "Ancient Mediterranean Cultures in Contact" exhibition

A glass pitcher that survived the volcanic eruption in Pompeii in 79 A.D.

One of the Field Museum's conservation labs

A mount shop employee works on the base of a small sculpture

A mount shop employee readies a piece of metalwork for display

Even large object pass through the Field Museum's mount shop

Shelves and display cases are manufactured in the Field Museum's woodshop

The Field Museum's woodshop packs a lot of equipment into a tight space

As one of the first paintings that Greek artist El Greco completed upon arriving in Spain in 1577, The Assumption of the Virgin has long been a centerpiece of the Art Institute’s collection. At more than 400 years old, the 13-foot-tall canvas passed through many hands before the museum acquired it in 1906 (it previously hung on the altar of a church in Toledo, Spain). “Anything that has any kind of age has gone through cycles of neglect and restorations,” says Grainger Executive Director of Conservation Frank Zuccari, which is why the masterpiece is mounted sideways in the museum’s conservation space where it is being painstakingly restored (thanks to a grant from Bank of America).

The small climate-controlled room serves as a temporary home for various artworks being preserved for future generations. It’s here that the conservation staff creates careful records of each painting, studying the conditions of their surfaces, combing over documentation of past restorations and using ultraviolet photography, infrared imaging and radiography to look past the outer layers. Zuccari spent four weeks staring only at the already-dry paint of The Assumption of the Virgin, forming a detailed plan of action for its upkeep.

The process of cleaning and preserving the painting and its frame is one that Zuccari estimates will take up to six months (another painting in the room has been there for three-and-a-half years). “Preserving the original intention is important,” says Zuccari, noting that the restoration of a work of art should never be rushed. “You’re trying to preserve the original structure but also the visual integrity.” After a few more months in the conservation room, The Assumption of the Virgin will be back in the gallery, looking better than ever and ready to serve as a backdrop for countless selfies for years to come.

El Greco's The Asumption of the Virgin mounted sideways in the Art Institute's restorarion room

An Art Institute employee wearing a headband magnifier carefully cleans a painting

Granger Executive Director of Conservation Frank Zuccari in front of El Greco's The Asumption of the Virgin

Restoring a painting is a painstaking process that can sometimes take years

Granger Executive Director of Conservation Frank Zuccari points out the progress that has been made in the restoration of The Asumption of the Virgin

Patrick G. and Shirley W. Ryan Associate Curator of European Painting and Sculpture speaks with Frank Zuccari