I treated Study of a Female Head by William Morris Hunt (1872). Part of the treatment was an installation of an insert backing. An insert backing was needed for two reasons: there was some slight sagging and draws, and the painting was going to be hung lower on the wall than is typical. The draws could in theory have been keyed out, but the stretcher was already somewhat keyed out and there was a concern about opening up the corners too much. An insert would support the canvas to partially reduce the canvas distortions. It also serves as a physical barrier to reduce damage if anything were to poke at the front of the canvas, as there is basically no cavity to poke into.

The insert is made of Tycor, which is cut to fit into the stretcher cavity. The corners can be cut down to accommodate any keys present. I glued strips of barrier paper around the edges with Jade 403, to prevent any dust or insects from accumulating into the crevices of the Tycor interior. With that prepared, I rolled a layer of Volara on to the side facing the canvas attached with archival low melt hot glue. I attached the Tycore-Volara board to the coroplast backing with a series of archival low melt hot-glue dots, then “caulked” the sides with a bead of hot glue to make sure there is solid adhesion.

While the Volara layer is necessary, it made the insert slightly too thick, so I added strips of matboard around the edge of the coroplast backing board. The matboard strips raised the insert so it was level with the interior edge of the stretcher bars.  I cut notches at the corners because there were delicate tabs of canvas at the corners I wanted to avoid crunching down with the backing board.