41st Annual Meeting-Book and Paper Session, May 30, "Treatment and Housing Techniques for Pastel Paintings on Paper-Case Studies" by Soyeon Choi and Jessica Makin

Soyeon Choi, Senior Paper Conservator, and Jessica Makin, Manager of Housing and Framing Services, divided their presentation into two parts: first they addressed the treatment of one individual pastel portrait, then they described a variety of housing options used at the Conservation Center for Art and Historic Artifacts, a regional conservation center in Philadelphia. The treatment and rehousing protocols were all intended to reduce the loss of friable pastel image material and to protect the weak (often brittle) paper support.  All of the examples were originally mounted onto wooden stretchers or strainers, further complicating treatment and rehousing efforts. Most of the items also retained original frames or period frames.
Soyeon Choi began by describing the work of folk artist Micah Williams (1782-1837), who was active in the early 19th century.  He created 274 known portraits, and he tended to line them with newspaper, a fact that has provided valuable provenance and date information.  The first case study portrait was mounted onto a white pine stretcher, and treatment was performed in situ.
Micah Williams pastel  2
Soyeon Choi showed how she used a mockup of  a complex, sprung tear to devise a sympathetic repair for one of the portraits.  Repair adhesives were determined by the location of the tears. In general, Klucel G was strong enough to hold most tears, yet weak enough that it didn’t place too much stress on the fragile paper support. Klucel was applied to thin kozo in advance, and individual  repair strips were reactivated with ethanol when needed.  More traditional wheat starch paste repairs were possible on the edges where the paper was in contact with the strainer and more pressure could be applied safely. Lascaux 498 HV was also used for some pastels, but I didn’t hear exactly what mix was used or how it was activated.  Choi also explained how she used ground pastels, powdered colored pencils, and dry pigments with ethanol to inpaint losses in the portraits.
Micah Williams pastel 1
In the second half of the presentation, Jessica Makin showed photographs and diagrams of different spacer configurations and frame profiles. The spacers were wrapped with toned, 1-ply Bainbridge matboard that was attached to the lignin-free, corrugated board with 3M 415 tape. Most of the frames were altered by building up the backs to accommodate the additional thickness of the spacers and glazing. In the case of a pastel by Mary Cassat, the frame could not be altered, so Makin constructed a tray with thin sides to contain the pastel and the glazing, while also supporting the glazing away from the media surface.
I feel that this  presentation loses a lot without the photographs and diagrams, so I will ask the authors to share a link to images of at least one example to better illustrate their work.