2 PAINTING STRUCTURE AND CONDITION

The painting, measuring 93.0 � 77.3 cm, was attached to a four-membered softwood stretcher with metal tacks spaced 4–6 cm apart. The picture was executed on a fine, tightly woven, plain-weave linen canvas having a thread count of 15 warp and 14 weft yarns per cm. Both of the yarns had z-twists. Selvage edges were extant on both the left and right edges of the canvas; the warp yarns had a vertical orientation.

Microscopic examination revealed that a glue size layer had been applied to the linen canvas before priming. Under magnification the glue size appeared as a distinct layer that coated the yarns of the canvas. The canvas was commercially primed with a thin, off-white oil ground, and the image layers were executed with pigments in a drying oil medium. Examination under ultraviolet light confirmed the existence of extensive overpaint along the left side and bottom edge. The painting had a surface coating of natural resin varnish, which was moderately discolored and partially blanched.

The flood damage resulted in major alterations to each layer of the painting. The canvas was extremely weak and degraded; although it had undergone considerable shrinkage and tightening upon wetting, it was slack on its stretcher after drying. There were numerous tears along the turnover edges and tacking margins, many originating from the tack points. The paint and ground layers exhibited large amounts of tented cleavage; although these layers were severely distorted and very brittle, they remained remarkably intact with relatively few losses.

To comprehend why this type of damage occurs in some paintings more than in others, it is necessary to examine how each of the painting components react to water and how they interact with each other.