Merriam-Webster Collegiate Dictionary - stipple

 I. transitive verb  (~d; stippling)  Etymology: Dutch stippelen to spot, dot  Date: circa 1762  1. to engrave by means of dots and flicks  2.  a. to make by small short touches (as of paint or ink) that together produce an even or softly graded shadow  b. to apply (as paint) by repeated small touches  3. speckle, fleck  • ~r noun  II. noun  Date: 1837 production of gradation of light and shade in graphic art by stippling small points, larger dots, or longer strokes; also an effect produced in this way