Canvas-related micro-cracks in Danish 19th century paintings

This paper discusses the emergence of microcracks observed in the ground layers of paintings on canvas supports. Such cracks are visible in 50 μm resolution x-radiographs and correlate with the occurrence of microcracks as well as more large-scale crack patterns in the surface of the paintings. They also explain the initiation of one type of crack formation and the subsequent propagation of the crack into the paint layers. An examination of 41 paintings by the Danish artist C.W. Eckersberg, dating from throughout his oeuvre, showed a variable prevalence of microcracks in 24 paintings. Some cracks were visible only in the x-radiographs while others could be observed also on the paint surface. In many cases, it was found that microcracks were incorporated into the larger crack pattern of the paint. The mechanical process underlying the genesis of microcracks is discussed, and a potential association with the stratigraphy of the grounds used in Eckersberg’s paintings is proposed.