I made a lot of hard edge paintings during that time and by the Fall of 1965 I finished a series of drawings of my next and really first series of mature paintings. (ronnielandfield.com)
Hard Edge Painting Term coined in 1959 to describe abstract (but not geometric) painting, using large, flat areas of colour with precise edges. (visual-arts-cork.com)
This balance makes up her definition of Hard Edge painting — wherein color forms are positioned against each other, alternating between being a positive or negative space. (lamodern.com)