This exhibition consisted of approximately sixty landscape oil sketches from the collection of the art historians John and Charlotte Gere. Dating from the seventeenth to the nineteenth centuries, these small, rapidly-executed sketches on paper, panel, or canvas were painted outdoors by artists across Europe to sharpen their skills of perception and execution; they were rarely intended for public exhibition. Pioneers in the collecting of oil sketches — which have only lately gained wide appreciation — the Geres assembled some eighty works over a period of forty years beginning in the 1950s. The selection presented a survey of the oil-sketch tradition as practiced by British, French, Italian, Belgian, Spanish, and Scandinavian artists, many of whom worked in or around Rome, where the practice of open-air sketching flourished. Works by such painters as Corot, Degas, Valenciennes, de Nittis, Simon Denis, Thomas Jones, and Lord Leighton were included, as well as some by artists as yet unidentified. The exhibition represented a milestone in the study and understanding of a vital tradition in European painting. Organized by Christopher Riopelle for the National Gallery, London, where it was first shown, the exhibition was accompanied by a fully illustrated catalogue by Riopelle and Xavier Bray, with an essay by Charlotte Gere.