Have you ever wondered what it takes to get a 21-foot-wide painting up onto a museum wall? More than a hammer and nails, to be sure! We recently installed Cy Twombly‘s monumental Untitled (1970) in MoMA’s main lobby—an undertaking that required a crew of nearly 20 skilled staff members, two forklifts, five hours, and a bevy of staples.

The installation coincided with a memorial that the Museum organized for Twombly, who passed away on July 5 at age 83. It joins a group of seven recently acquired sculptures and three other paintings by the artist that will remain on view in other areas of the Museum through the end of the year.

Twombly was a key member of the generation of American artists immediately following the Abstract Expressionists. Untitled is the largest in a series of works on gray grounds that he produced between 1967 and 1971. The painting, rendered in oil-based house paint and white Caran d’Asche crayon on canvas, features jagged- and curved-edged scrawls, reminiscent of chalk on a blackboard, that form no actual words. To create his fluid, continuous lines even in the upper register of the work, Twombly reportedly sat on the shoulders of a friend, who shuttled back and forth along the length of the canvas.

Because of its mammoth scale (it measures 13′ 3 3/8″ x 21′ 1/8″), Untitled is stored rolled around an archival tube, separate from its stretcher. Each time the work is hung, a team of in-house and outside experts come together to stretch the canvas anew on a network of stretcher bars in situ, since it is too big to maneuver through doorways or elevators in its sprawling final form. (This is the fourth time the work has been installed in the Museum since MoMA’s 2004 renovation.) What follows is an illustrated play-by-play of that process, which took place one recent evening after the Museum closed to the public.

First, we put together the stretcher, which is stored in three pieces. The reinforced grid of crossbars provides additional support and prevents the extra long canvas from slackening in the center.

We covered the marble floor of the lobby with cardboard to provide a foundation layer of protection, and then positioned the massive roll over it.

Then, we let it loose! The extremely fragile painted surface was overlaid with a sheet of archival mylar for protection when the canvas was last prepared for storage. So as we rolled the canvas off of its storage tube and laid it face down onto the floor, the protective mylar came with it and acted as a barrier between the painted surface and the covered floor.

Next, we laid the stretcher across the top of the back of the canvas…

…and aligned the stretcher so that there was an even amount of slack extending beyond its edges all the way around. We also affixed rope to the top of the stretcher. You’ll see why in a moment.

After tethering 2x4s to the back of the stretcher to keep its weight off the canvas during the stretching process…

…we started stapling! We pulled the tacking edge of the canvas up and over the stretcher bar, and stapled it at regular intervals along the back edge.

Once the canvas was stretched and the 2x4s were removed, our crew grabbed hold of the ropes affixed to the top portion of the stretcher and got into position. Notice the strip of wood on the wall visible in the background of this photograph. That’s part of the cleat: it interlocks with a mirrored wooden strip on the back of the stretcher to form the structure responsible for holding the work up on the wall.  This method allows for a more even distribution of weight than traditional mounting devices, such as hooks, and is therefore often employed when hanging large, heavy works. We had already determined the height at which the work would be hung, based on what our conservators recommended to be a safe distance from the floor. But the cleat system allows for flexibility in placement, as the painting can slide left and right along the cleat on the wall.

Then, they began to pull on the ropes to hoist the painting up to meet the wall.

When the work was upright, directly beneath the cleat, one team lifted the work off the floor and rested its bottom edge on the padded blocks sitting on manual hydraulic lifts, while other crew members steadied the work from above.

The crew members on the floor raised their manual hydraulic lifts to elevate the painting high enough to engage the cleat on the wall. The crew working from above then carefully slid the painting along the cleat while the curator made adjustments to determine the final placement. And—voilà!—our work was done. It was a lengthy, involved, and, at times, nerve-wracking project (it’s not every day that a masterpiece is lying face-down on the floor!), but an equally fascinating one, thanks to a fabulous team of experienced, talented conservators and art preparators.

We hope you have an opportunity to see this very special painting, on view at the Museum through November.