Frederick Hammersley was an American abstract painter. His participation in the 1959 Four Abstract Classicists exhibit secured his place in art history.

Karl Stanley Benjamin was an American painter of vibrant geometric abstractions, who rose to fame in 1959 as one of four Los Angeles–based Abstract Classicists and subsequently produced a critically acclaimed body of work that explores a vast array of color relationships. Working quietly at his home in Claremont, CA, he developed a rich vocabulary of colors and hard-edge shapes in masterful compositions of tightly balanced repose or high-spirited energy. At once intuitive and systematic, the artist was, in the words of critic Christopher Knight, "a colorist of great wit and inventiveness."