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| Figure 8 Sample from the left side of the upper case, average surface thickness 0.45 microns. (Photo, Winterthur Museum.) This sample was taken from a protected area on the back edge of the side. A reactive dye was added to this section to cause the oil layers to fluoresce orangered. The surface stratification of samples in figs. 5-7 is repeated with the exception of the uppermost layer (8.5) that corresponds with 5.6 in the standard sample. It is clear from the deep, orange-red fluorescence of layers 8.2 and 8.3 that the original finish included oil mixed with a resin. |