During the recent restoration of Rembrandt's Anatomy Lesson of Dr. Nicolaes Tulp minuscule crater-like holes, which cover the surface of the painting, were studied. Whitish material within the holes was identified as lead chloride hydroxide and a variety of lead soaps. These inclusions, which in many cases protrude through the paint, are thought to have formed as a result of the agglomeration of lead compounds and saponification of the linseed oil within the ground layer. Possible scenarios for the origin of the chloride are discussed.

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J. Goupy , J.-P. Mohen

Noble, P., Wadum, J., Groen, K. M., Heeren, R., & van den Berg, K.-J. (2000). Aspects of 17th century binding medium: inclusions in Rembrandt's Anatomy Lesson of Dr Nicolaes Tulp. In J. Goupy & J.-P. Mohen (Eds.), Art et Chimie, la Couleur: Actes du congrès (pp. 126–129).