Panel Painting - Conservation and Scientific Analysis

Conservation and Scientific Analysis

Wood panels, especially if kept with too little humidity, often warp and crack with age, and from the 19th century, when reliable techniques were developed, many have been transferred to canvas or modern board supports.

Wood panel is now rather more useful to art historians than canvas, and in recent decades there has been great progress in extracting this information - and many fakes discovered and mistaken datings corrected. Specialists can identify the tree species used, which varied according to the area where the painting was made. Carbon-dating techniques can give an approximate date-range (typically to about a range of about 20 years), and dendrochronology sequences have been developed for the main source areas of timber for panels. Italian paintings used local or sometimes Dalmatian wood, most often poplar, but including chestnut, walnut, oak and other woods. The Netherlands ran short of local timber early in the 15th century, and most Early Netherlandish masterpieces are Baltic oak, often Polish, cut north of Warsaw and shipped down the Vistula, across the Baltic to the Netherlands. Southern German painters often used pine, and mahogany imported into Europe was used by later painters, including examples by Rembrandt and Goya.

In theory, dendro-chronology gives an exact felling date, but in practice allowances have to be made for a seasoning period of several years, and a small panel may be from the centre of the tree, with no way of knowing how many rings outside the panel there were. So dendro-chronological conclusions tend to be expressed as a "terminus post quem" or an earliest possible date, with a tentative estimate of an actual date, that may be twenty or more years later.

The so-called Panel Paintings Initiative is a multi-year project in collaboration between the Getty Conservation Institute, the Getty Foundation, and the J. Paul Getty Museum. The Panel Paintings Initiative is a response to the growing recognition that significant collections of paintings on wood panels may be at risk in coming decades due to the waning numbers of conservators and craftspeople with the highly specialized skills required for the conservation of these complex works of art.