In his most famous works, Jackson Pollock used a technique known as drip painting to construct tangled messes of filaments. He used house paint, which is much thinner than traditional oil paints, and dripped it onto canvases laid flat on the floor, with a range of tools including sticks, syringes, and even the paint can. Although Pollock was not the only 20th-century artist to employ drip painting, his approach and the unique features it generated have intrigued not only art historians but also scientists. (For more details about the underlying fluid dynamics, see the article by Andrzej Herczyński, Claude Cernuschi, and L. Mahadevan, Physics Today, June 2011, page 31.)
To better understand Pollock’s technique, Bernardo Palacios, Roberto Zenit, and coworkers at the National Autonomous University of Mexico and Brown University analyzed video recordings taken of the artist at work by documentarian Hans Namuth. The recordings captured both the side-view perspective and some bottom-up clips in which Pollock is painting on a transparent pane of glass. Tracking analysis of the films yielded Pollock’s hand speed, the height from which the paint dripped, and, indirectly, the flow rate of the fluid leaving the painting implement.
The researchers then mapped the phase space of painting parameters using a supplementary experiment: a syringe pump depositing paint onto a moving canvas. In particular, they looked at which conditions resulted in a coiling instability and caused the paint jet leaving the syringe to double back on itself, forming curls on the canvas. Pollock’s painting action almost entirely avoided the range of parameters associated with a coiling instability and instead generated straight lines. The curves in the paint came instead from the artist’s intentional motion. That finding is consistent with inspections of his work, such as Number 14: Gray, a small piece of which is shown in the figure. To see an example of the curling instability in his work, look at the oscillating red lines in the 1948–49 painting Untitled.
Pollock’s technique also avoided a fragmentation instability, so the paint filaments maintained their integrity instead of breaking up as they fell toward the canvas. Recognizing such traits in paintings may prove useful in authenticating Pollock’s works. (B. Palacios et al., PLoS ONE 14, e0223706, 2019.)
