Pointillism marks (4)
I believe the answer is:
dots
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pointillism marks</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for dots that I've seen before include "Small marks" , "Tiny circular shapes" , "Tiny spots" , "Tiny circles" , "Short signals in Morse cods" .)