As masterpieces on a small scale, paintings on copper have a broad appeal to the public and especially to collectors. From the time of the earliest known, in Italy in the 1520s, the conception and creation of these paintings are rooted in the ambition and curiosity of artists to innovate both technically and theoretically, to enhance the images and conceits which they, and their influential patrons, were striving to achieve. The emergence of paintings on copper and other unusual supports arose in the spirit of experimentation in early sixteenth century Italy and spread throughout Europe and Spanish America. This paper does not present a definitive narrative of the practice of painting on copper and other unusual supports, rather it explores the possible contexts in which they appear to have developed. In this sense, the art historical, and technical art historical study of unusual supports has come a long way since a small exhibition in London in 1867, and van der Graaf’s and Andrew’s pioneering work in the 1970s. The major interdisciplinary research project culminating the international touring exhibition ‘Copper as Canvas’ in 1998-9, focused on a broad range of art historical, technical and economic activity, from which more general Renaissance studies, technical art history and conservation science continue to feed.