Oil on copper painting is the process of creating artworks by using oil paints with copper as the substrate. This is sometimes referred to as "copper as canvas" because canvas is the most well known surface material used for oil paintings.
The Francesco St Jerome
Dead Frog with Flies
Carlo Saraceni - An Angel Appearing to the Wife of Manoah
Guido Reni - St Francis Consoled by Angelic Music
Carlo Saraceni was an Italian early-Baroque painter, whose reputation as a "first-class painter of the second rank" was improved with the publication of a modern monograph in 1968.
Anonymous, Portrait of Carlo Saraceni (1616)
Saint Cecilia and the Angel
The Madonna and Child with Saint Anne and an Angel, oil on copper, c. 1608–1610, Honolulu Museum of Art
The Vision of St Francis (circa 1615)