테오도루스 스크레벨리우스의 초상

It is the size of a postcard, painted on copper rather than panel or canvas, and it exists because of a print. In 1618 the Haarlem engraver Jacob Matham copied it onto a plate, and small oils like this were what an engraver worked from.

The sitter is Theodorus Schrevelius, headmaster of the Latin school in Haarlem. In a history of the town published 31 years later, he wrote that Hals painted his portraits with such force and life that they seemed to breathe. That is the earliest praise in print of the loose brushwork people now travel to Haarlem to see.

Specialists have disagreed about the picture itself. Seymour Slive listed it among Hals's own works and Claus Grimm as a copy after him, while the museum catalogues it under Hals.