 According to writer and curator Barbara Haskell, who wrote the introduction to the catalog for Mason's 1974 retrospective at the Pasadena Museum of Art, "These pieces have a monumentality and physical size that had no precedent in contemporary ceramics".A subsequent series represents a more conceptual approach to Mason's interest in mathematics, one that is concerned less with the physical properties of clay as a medium and more with what those properties allow one to represent.As Richard Marshall wrote