The pigment smalt is the most important blue pigment in Rembrandt’s paintings. It is also used in The Night Watch.
The most important blue pigment in Rembrandt’s Night Watch
Rembrandt used smalt not only for its blue colour, but he also mixed it with red to make a purple, and with yellow to make a green, and to enliven his brown mixtures. He also used smalt to thicken his paint and to make it dry faster.