Copper is a type of metal sometimes used as a support for small paintings. Because of the method of its manufacture, it was not available for large works, but provided an ideal smooth surface on which to paint small pictures in which there was much detail.
Works of this type, such as those by Elsheimer and Schalcken in the Collection, have an enamel-like finish.
The earliest paintings on copper date from the late 16th century and its popularity was probably connected with the availability of copper plates for engraving. Other metals were sometimes used - for example silver, tin and (in the 19th century) zinc.