The carved and gilded wooden frames around the eight monumental paintings in the Capitol Rotunda installed in 1824 have now all been completely conserved for the first time in half a century.

Conservation work began in September 2004 with the frame of Signing of the Declaration of Independence. The conservators first treated a pilot section to test cleaning methods; the results were reviewed and approved by the curator for the Architect of the Capitol, with the concurrence of the House and Senate curators and an advisor frame conservator from the National Gallery of Art. Work then proceeded on that frame and progressed from frame to frame around the Rotunda. The scaffolding erected to give conservators access to the frames had to be removed for special events and ceremonies. The work was completed in early March 2006.

When he was completing the construction of the Rotunda in the 1820s, architect Charles Bulfinch designed these frames; today, they are among the most historic elements in the building. Each frame measures 16 by 22 feet and is made of pine. Rosettes embellish each corner. The frames were in place by 1824, when the four paintings by John Trumbull were installed, and were gilded in 1826-1828. Repairs, slight modifications, and partial regilding were performed in 1890, 1905, and 1953. No records of any major campaign of repair and regilding in the last half-century have been found, although the frames may have been touched up after the cleaning of the walls in 1974.

A 1999 study of the frames documented their condition and recommended the work needed. The lower areas of the frames were especially worn and in some places were disfigured by graffiti, abrasions, dents, and stains. Some pieces of the carved elements and areas of gold leaf were missing. The surface of the gold was dulled and darkened with discolored coatings and grime. Sunlight, some leaks or drips, and human hands caused most of the damage.

The recent treatment preserved as much of the existing historic material as possible while cleaning and consolidating surfaces, restoring losses, and bringing the gilded surfaces to an even appearance. The professional conservators cleaned all of the frames' gilded surfaces, stabilized the existing coatings, and replaced missing elements. They then applied new 23-karat gold leaf where needed, following the original process. First, the wood was prepared with a coat of gesso (a mixture of plaster and glue). Where the Greek key elements were in poor condition, they were water gilded over a layer of bole (a gray clay-based material), burnished, and polished with an agate tool. Many of the rosettes were broken and covered with bronze powder paint. They were removed for cleaning, repair, and regilding. On the rest of the frame, oil gilding was done to produce a matte appearance. Finally, to match the cleaned original surfaces from the 1905 regilding campaign, a tone consisting of shellac and a mixture of pigments and resin were applied. The conservators were challenged by the ever-changing lighting conditions adjusting the tone on the frames and in protecting the paintings themselves from any damage.

This project has restored the beauty and integrity of the frames and will enhance the appearance of the paintings. Detailed reports were prepared on the conservation of each frame. During the course of the treatment, and after examining over 100 samples under a microscope, the conservators discovered that the earliest gilding was with a "green gold" similar to modern 18-karat gold. They were able to match the layers they observed with archival records and conclude that the gilding on four of the frames was done by Isaac Cooper and that Thomas Palmer and Ephraim Gilman each gilded two frames.

Frame around Surrender of Burgoyne before conservation
Damaged corner rosette before conservation	Repaired, regilded, and toned corner rosette after conservation