2. Examination of Paintings at IUAM
Scott Williams visited IUAM during the week of July 13-19, 1996. With Margaret Contompasis and Danae Thimme, paintings and other objects on display at the Art Museum and the Lilly Library of Indiana University were examined, in situ, with the naked eye. During this examination the phenomenon attributed to contamination by DEAE from the humidification system was observed. The phenomenon appeared primarily as a disruption of gloss in the form of a bluish film or haze on the surface of paintings, most noticeable over dark colored areas.
Additional paintings were examined more closely in the conservation laboratory by microscopical methods. A second phenomenon attributed to DEAE contamination was observed on these paintings. When some paintings are swabbed with water moistened swabs in areas showing the bluish film or haze, the film is removed, and the area develops a whitish hazed appearance. Continued swabbing with water moistened or saliva moistened swabs removes the hazed appearance from the area, and restores the healthy appearance to the varnish or paint film.
Samples were taken from these paintings by Scott Williams and Margaret Contompasis for chemical analysis at CCI.
3. Sample selection and collection
Samples consisted of wipings on small cotton swabs, powders and particles obtained by scraping the surface of the painting, or particles or flakes excised from the painting with a scalpel. Samples were taken from areas of paintings that showed effects attributed to the presence of DEAE such as hazy or greasy appearing surfaces, varnishes that became abnormally hazy or milky when swabbed with water, etc.
Cotton for swabs was prewashed with methanol. Swabs were prepared by wrapping a small wad of cotton batting around the tip of stainless steel forceps. Gloves were worn when wrapping the swabs to prevent transfer of fingerprints. The swabs measured about 2 mm diameter by 5 mm length. Wipings were done either with dry swabs or with deionized water moistened swabs. After wiping the surface the swabs were removed from the forceps and stored in glass vials closed with teflon/silicone septa with the teflon side facing inwards.
Scrapings were made by dragging a scalpel across a prescribed area of the painting surface in such a manner than only a single layer was removed, and usually only the upper surface of that layer. The operation was carried out while observing with a stereomicroscope. Scrapings were removed with the scalpel or a needle and transferred either to septum cappedglass vials or microscope slides. Samples on microscope slides were covered with another microscope slide then the two slides were taped together to trap the sample between them.
Particles or flakes were excised from the painting surfaces using a scalpel, then transferred and stored in septum capped glass vials.
Additional samples, taken by others more than a year prior to Williams’ visit, were supplied by Margaret Contamipasis. These samples consisted of water moistened swabs and powders brushed from the surfaces of paintings. They have not been stored in air-tight containers. Some of these samples were analyzed by gas chromatography at the Chemistry Department of Indiana University by Greg Barrett-Wilt (1996).
All samples are described in Appendix A.