Christopher Farr has been at the spearhead of contemporary rug design for over twenty years. Together with his business partner Matthew Bourne, they were the catalyst that revolutionised contemporary rug design. The commission for Bank of America Plaza are five custom tapestries, made of hand-spun wool and mohair, with the largest measuring 20 feet by 41 feet high.

Calder developed the design, size and scale of "Four Arches" by working with architectural drawings and a model of the site. He then built a maquette of the work. Fabricated out of carbon plate steel, "4 Arches" was installed during the construction of the surrounding plaza. The sculpture was aligned by Peter Walker, the landscape architect, and painted "Calder" red, which is actually an orange-red. Creating a striking contrast against the muted colors Albert C. Martin and Associates incorporated into their design of the adjacent 52-story office tower, the sculpture has a high profile on Bunker Hill, serving as a distinctive landmark, and as a frame for the surrounding buildings.