FORS
Researching the pigments and binding media
The surface of The Night Watch has been extensively studied using various imaging techniques. However, sometimes additional research is needed to further characterise the painting materials and to gain a better understanding of why Rembrandt made certain choices.
How does it work?
Researchers carried out spot measurements with a technique called Fiber Optic Reflectance Spectroscopy (FORS). The principle of this technique is relatively simple: the painting is illuminated with a light source, and the light reflected from the painting is collected with a fibre optic. The pigments and binding media in the painting each reflect the light back in a different way and can be characterised in this way.
Researching without touching
Because FORS is a small and portable instrument, researchers can easily move it in front of the painting without touching the paint surface. With this technique, we specifically looked at areas of well-preserved red lakes, exposed ground, impasto, as well as damaged areas.