It's essentially thick patches of flaky yellow spots on the scalp that can create bald spots if you handle it incorrectly. (policygenius.com)
The colors build and subside across the heavy downpours of paint, which often erupt in thick patches of splashes and splatters, or dissipate into exposed bits of canvas.» (twocoatsofpaint.com)
The subject is enhanced by Rouault's technique of laying thick patches of paint on his canvases, so that undercolors glow through to the surface. (religion-online.org)