Book excerpt: "How paintings were made--in the most literal sense--is an important but largely unknown aspect of the story of American art. This book, like the authors' previous volume on American painting techniques from the colonial period to 1860, is based on descriptions of the materials and methods that painters used, as found in artists' notebooks, painting manuals, magazines, suppliers' catalogues, letters, diaries, books, and interviews. In interpreting this evidence, the authors have made use of their experience as conservators who have treated many important American paintings."--Book jacket.