the.com/stippling

means Creating a picture or shading an area using many small dots rather than lines or strokes.

from From 'stipple,' borrowed in the 1600s–1700s from the Dutch/German 'stippel,' a little point or speck, itself tied to 'stip,' meaning dot. Engravers picked it up to describe the technique of building tone from a swarm of tiny punctures rather than lines — a slow, patient alternative to cross-hatching that spread from printmaking into painting, tattoo work, and even dentistry's pitted composite finishes.