It is especially gratifying to witness the convergence of results of research that has been performed using entirely different approaches and methods. Jacqueline Marette’s book is an extreme example of this, combining as it does the conclusions of what would appear to be two mutually distant fields of study – the history of art and wood anatomy – in a way that increases our knowledge of historical forest vegetation and the woodworking industries, as well as that of painting techniques.
These findings are firmly underpinned by a considerable number of samples – more than fifteen hundred in all – enabling us to infer certain general rules with a probability close to certainty. This with the proviso, however, that in the majority of cases, the analysed wood fragments were tiny and that for certain genera, most notably Quercus, it was not possible to narrow the sample down to a particular species or group of species. It is difficult, if not impossible, to determine whether a splinter of late wood 1Cf. Chapter 2, ‘Wood technology’. comes from a deciduous or an evergreen oak, even though the two can be readily distinguished by the naked eye in a sample encompassing the full width of an annual growth ring. Despite this constraint on the precision with which the genus could be determined, the results as a whole reveal, through the numerical proportions of each such genus, that the varieties found among the painting supports of a given region are, with few exceptions, the dominant ones. These dominant varieties are precisely the ones that form the core of the forest populations of each region and which therefore furnished almost all the wood used for construction and joinery. Artists drew the raw material for their supports from the woodworking industries and wood trade in the region where they lived. They were not driven to seek types of wood that were less common but which offered certain properties that might have made them preferable. Italian painters did not reject poplar, despite its low resistance to destructive agents, any more than their German counterparts turned their noses up at fir, spruce, pine or lime, all of which share the same drawback. Painters seem to have gone no further than to reject those varieties among the types of wood available on the local market, which are prone to shrinkage 2Reduction in the volume of the wood. This physical phenomenon occurs as the wood dries out, above the fibre saturation point. Shrinkage varies according to the nature of the wood (Campredon 1949: 46). and hence less suitable for high-quality panels. This would explain the low proportion of beech among the supports used by German painters, who preferred to work with other readily available varieties that display only moderate shrinkage, such as deciduous oak, fir, spruce and Scots pine; or low shrinkage, such as lime. The same pattern might have led southern European painters to reject green oak. Generally speaking, however, ease of purchase was the only criterion by which artists selected their wood. It is striking in this regard that solitary varieties that commonly feature within the tree population are rarely represented among the analysed supports, even when their wood offers the necessary properties, as is the case with elm, rowan, sorb, wild cherry and maple. Taken together therefore, painting supports offer a representative sample of the forest vegetation, in which everything that is rare in nature proves to be equally rare as far as the manufactured object is concerned.
This study also offers precious clues regarding the date at which exotic species, particularly walnut, were introduced. Lastly, the section devoted to the construction of the panels cites a range of documents that are of great interest to the history of woodworking methods and tools. The forest botanist, the wood technologist and the historian will, therefore, all discover exceptionally interesting data in this book concerning forest flora and the historical links between human industry and natural resources.
Conservator of Rivers and Forests, Research Director at the Centre Technique du Bois
1 Cf. Chapter 2, ‘Wood technology’.
2 Reduction in the volume of the wood. This physical phenomenon occurs as the wood dries out, above the fibre saturation point. Shrinkage varies according to the nature of the wood (Campredon 1949: 46).