The term abrasion describes one of the aspects that determine the current appearance of The Night Watch. Abrasion means that the original paint has been removed, literally worn off, sometimes even down to the threads of the canvas support. This was often caused by the inappropriate application of (unsuitable) restoration materials during the many treatments that the painting underwent in the past.

Areas of dark paint

Areas of dark paint are often extra sensitive to overly aggressive restoration materials, making them generally more abraded than lighter areas of paint. Banninck Cocq's black costume on The Night Watch is a clear example of this. In a lot of places the paint is abraded down to the brown ground underneath, so that the modelling of the fabric is now difficult to read.

Faces

Many of the faces on The Night Watch have also suffered from past treatments. A clear example is the face of the so-called red musketeer, Jan van der Heede in figure 2; especially in the shadows of his face abrasion is significant.

Efficient

However it is also important to realize that during painting, Rembrandt himself made efficient use of the brown colour of the ground, which he let show through here and there, and sometimes even left completely uncovered. It is not often easy to make a clear distinction between abraded areas and painting technique.

Foreground

A third example of abrasion, in which not only the paint layers, but also the ground, have been damaged, can be found in the foreground, in the area between the feet of Banninck Cocq and Van der Heede. If we zoom in here, we regularly see the tops of canvas threads exposed in the paint layers, or even areas where almost all paint and ground are no longer present, so that the canvas on which The Night Watch is painted is now visible.

Difficult

Even though we already know quite much about the treatment history of The Night Watch, it is still difficult to determine exactly in which period the said examples of abrasion originated. More likely, they have been the result of a cumulative effect of multiple treatments.