It’s called craquelure. (Forgive my short explanation. I have to get up in 4 hours.) In addition to applying thick layers of paint Rembrandt used varnish. All of this dries at different times, which leads to the cracking effect. It’s more a condition of how it was painted and the media the artists used and less about trying to achieve the effect outright.
Source: I have a phd in art history, and publish and teach in this field
Fun fact: the Night Watch is an inaccurate title. The title is actually Militia Company of District II under the Command of Captain Frans Banninck Cocq or The Shooting Company of Frans Banning Cocq and Willem van Ruytenburch. It’s known as the Night Watch because of dirt and varnish—the varnish yellows over time. This changed after extensive restoration. Also, the painting has been vandalized several times. In one unfortunate event in the ‘70s a person took a knife to it.
I’m a cultural historian and professor. My early work was on the development of video synthesizers by artists, engineers, educators, and technologists—mainly for non-commercial and artistic purposes. I visited HN for a decade before creating an account. Now, I find thoughtful and engaging conversations on HN. It reminds me that while many of us do not work in the same profession/field, the inquisitive nature of the posts and comments speak to our common interests and curiosity. I also get to learn from amazing people who have played a part in pioneering their fields respectively.