Dendrochronology used in the dating of painted oak panels in Britain is challenged, because it is assumed that the panels were from indigenous wood (see also AATA 22-583). Michael Baillie's criticisms of John Fletcher's methodology are explained: the sapwood estimate mustbe compatible with the timber's origin. Baillie's rebuttal is based upon his belief that the timber is not imported from the Baltic. A chronology for Baltic timber is currently being constructed in Warsaw; these dates will be significant for this controversy. If the oak is not indigenous, at best Fletcher's dates represent a floating chronology. According to Baillie, dendrochronology can never prove the authenticity of a painting, only the felling estimate for the timber, which can then be determined as compatible with the age of the painting. See also AATA 22-30 and 22-605. -- AATA