stipple
verb
[ ˈstɪp(ə)l ]
• (in drawing, painting, and engraving) mark (a surface) with numerous small dots or specks.
• "to finish, stipple the picture with the original base colour"
stipple
noun
• the process or technique of stippling a surface, or the effect so created.
• "these pictures combine his favourite techniques—wash, line, and stipple"
Origin:
mid 17th century: from Dutch stippelen, frequentative of stippen ‘to prick’, from stip ‘a point’.