Ellsworth Kelly Sculpture Conservation Treatment

Head Conservator Elizabeth Steele on the 8-month long conservation treatment of Ellsworth Kelly’s Untitled (EK927).

In 2005, to commemorate the opening of the new courtyard at The Phillips Collection, the museum commissioned Ellsworth Kelly to create a site-specific sculpture for its west wall, made possible through the generosity of Phillips Trustee the late Margaret Stuart Hunter. Untitled (EK927) is a large-scale bronze composed of two flat planes that are semi-circular, joined so that one lies parallel to the wall and the other juts forward in a V-shape. It reflects the artist’s enduring interest in reductive abstract shapes drawn from nature and architecture. Kelly oversaw its installation in 2006, deliberately choosing to mount the 1,500-pound sculpture at an angle, making the sculpture seem to defy gravity.

As with all outdoor sculptures, conservation treatments are periodically needed to maintain the work’s intended surface appearance after exposure to nature’s elements that slowly erode applied coatings and patinas over time. Strong sunlight, heat, humidity, freezing temperatures, snow, pollen, and other abrasive airborne particulates, in addition to scratches and rubs acquired over the years, caused the clear lacquer coating on Untitled (EK927) to cloud and the black patina to degrade.

On the advice of sculpture conservators, the Phillips decided to remove the deteriorated surface coating and patina and reapply a new black matte patina. Instead of reapplying a lacquer to protect the patina, the final surface coating of the sculpture is achieved with numerous applications of wax. A custom formulation of Treewax tinted with black pigments was created to maintain the flat matte black appearance desired by Kelly. We are grateful to the Ellsworth Kelly Foundation for underwriting the large-scale conservation treatment to restore this magnificent sculpture to its intended appearance.

In November 2022, a team of skilled art handlers painstakingly removed the sculpture from the courtyard wall, where it has hung for the past 16 years. Many of the same individuals involved with its initial installation were present. It was taken to ASCo in Manassas, Virginia, which specializes in refinishing outdoor sculptures. After the deteriorated surface was removed, the firm Bronze et al, Ltd reapplied a new patina. The sculpture was then reinstalled June 2023 by the same team of seasoned art handlers. The conservation department will continue to monitor the sculpture, washing it several times a year to remove any accretions and reapplying wax as needed to maintain the artist’s desired surface.

A Sculpture Changes Over Time

On view in Pour, Tear, Carve: Material Possibilities in the Collection is a virtual reconstruction of Antoine Pevsner’s Construction in Space, a sculpture made of Celluloid which has changed over time.

Working with Plastics
Antoine Pevsner was born in Russia and immigrated to France in 1923. He worked in a Constructivist style, inspired by the increasingly industrial world. Pevsner and his brother, artist Naum Gabo, were pioneers in exploring new media. They became fond of Celluloid (cellulose nitrate) for its flexibility and transparency; Pevsner used it to make Construction in Space (1929). However, this plastic changes color and deteriorates as it ages. Both artists abandoned it in favor of more durable materials such as acrylic and glass.

Left: Early photo of the sculpture before it began to decay. Right: Current deteriorated condition of the sculpture.

Close-up images of deteriorated condition

Duncan Phillips acquired Construction in Space in 1953. Three years later, when it was requested for an exhibition in France, Phillips noted the work’s fragility. The artist wrote to Phillips that if he sent the sculpture to the exhibition at the Museé d’art moderne, he would make the necessary repairs to the piece. The work went to Paris and repairs were made, but the plastic continued to deteriorate. In 1979, the work was sent to an exhibition at the Guggenheim Museum in New York. Conservators noted its severe discoloration and made repairs with yellow tinted epoxy to reinforce the once transparent object. Upon returning to The Phillips Collection, the object was placed in a wooden storage box and not shown again because of its poor condition. A handwritten note from 1987 indicates that pieces had “deteriorated” and it “needs re-gluing.”

Isolating the Sculpture
In 1996, conservators recommended isolating the object from the rest of the collection so that the acid off-gassing from the cellulose nitrate would not adversely affect other works in art storage. In 2015, a custom box was fabricated for Construction in Space and it was placed in a well-ventilated space in the storeroom with acid scavengers to absorb the off-gassing.

Inside of storage box with acid scavengers (long white bags). The green/yellow strips indicate the amount of off-gassing from the plastic.

A Virtual Reconstruction
Because the sculpture cannot be restored or exhibited intact again, conservators decided to preserve the work’s original appearance by making a virtual replica. Stefan Prosky, a 3-D animator and technology artist, made a virtual reconstruction of the sculpture using 800 digital images of the work and also studying early photographs.

In the Studio with Mimi Herbert

Simona Cristanetti, sculpture conservator, dusts Butterfly during the installation of the exhibition.

Mimi Herbert’s acrylic sculpture Butterfly, 2021, is among the works featured in Pour, Tear, Carve: Material Possibilities in the Collection. The fabrication process of this striking work intrigued museum staff. As part of an ongoing initiative to document the materials and techniques of works entering the collection, conservators and curators were pleased to conduct an interview with Herbert in January 2023. The interviews allow museum staff to learn more about the artists’ practice and assist conservators in developing plans for the care of works of art. The group was given a comprehensive tour through Herbert’s three-room studio and was introduced to her process, which included participating in the creation of a sculpture.

Paper maquette indicating dimensions and where folds will be made.

Herbert conceives her idea for a sculpture first by working with a paper maquette. During this phase, she determines the size of the sheet of acrylic that will be needed, and where the folds will be made.

Herbert with different colored sheets of acrylic against the wall that she obtains from a California supplier.

The acrylic is cut to the dimensions needed following the designs that she makes using the maquettes. The sheet is then laid on top of a custom-built table with a bank of heat lamps to soften different sections of the acrylic where she plans to make folds. Above, the right side of the orange piece of acrylic is being heated in order to be manipulated after becoming pliable.

Heating the acrylic sheet

Herbert observes the section of acrylic after being heated for a short time to see if it is malleable enough to fold. Phillips staff (left to right: curator Renee Maurer, conservator Lilli Steele, and curator Camille Brown) stand ready to assist the artist. Because of the intense light and heat, the artist and any assistants always wear dark goggles and heat resistant gloves for protection.

Moving the acrylic sheet

When the sheet is sufficiently softened, it is removed from the heat and placed on a worktable.

Folding the acrylic sheet

Herbert demonstrates how she makes the first fold, smoothing the heated edge of the acrylic with a soft cloth. The acrylic sheet cools and becomes unworkable in less than a minute so the artist and her assistants must work quickly.

Mimi Herbert, Durga Reclining, 2023

Several weeks later, the work that began with Phillips staff participation, entitled Durga Reclining, was completed by Herbert and her studio assistants. The painstaking complexity of her process can be fully appreciated after having followed her steps from inception of the piece through folding and manipulating the warmed acrylic sheets to arrive at beautiful abstract sculptures.