Focus on The Scholar at the Lectern and explain the Description.
The sitter wears a black hat, a grey-brown cloak with a hint of green, lined with dark brown fur, and a gold chain. The subject of old scholars and philosophers is popular in Rembrandt's oeuvre. The face of the man in picture is distinctive because of specific details such as the wart on the left cheek and the red nose, suggesting a concrete sitter.
The picture is painted on poplar panel. The Royal Castle paintings are therefore two of five examples where Rembrandt or his workshop might have used poplar panels. Rembrandt probably bought a small batch of such panels c. 1639–41 and experimented with them.
Royal Castle Rembrandt