"I paid twopence for the painting"
The British copper penny
was in existence from the early 18th century until decimalisation of the coinage in 1971. It was sometimes informally known as a copper.
There were twelve pennies to the shilling, and 240 pennies to the pound. An old penny, therefore, would have been worth approximately 0.42 of the post-decimalisation penny currently in use.
The copper penny's predecessor was the English silver penny which was first produced in the 8th century.