Mars and Venus as lovers.

Mars and Venus as lovers depicted on copper, dated 1609 and held in the National Museum in Warsaw, belongs to a specific category of small-scale painting on copper that became fashionable among northern European collectors in the early seventeenth century. The copper support — used by Elsheimer and his circle in Frankfurt, and widely adopted across northern and central Europe in the first decades of the seventeenth century — permitted extraordinarily fine, detailed execution on a small scale and produced a surface luminosity quite different from canvas. Cornelis van Haarlem's choice to paint on copper for this work suggests either a specific commission for a cabinet piece or an awareness of the medium's fashionable status among the collector class he was courting. The subject — the adulterous embrace of the war god and the love goddess, typically caught by the cuckolded Vulcan's net — was a standard Mannerist pretext for the double nude.

Copper support with exceptionally smooth paint surface. The metal ground permits finer detail and more precise rendering than canvas while providing a naturally luminous reflection that enhances skin tones. The small scale demands tighter, more precise brushwork than large-format canvas work, and Cornelis adjusts his technique accordingly.