Knox Martin and the sculptors Ronald Bladen, George Sugarman and David Weinrib. In 1964, Held was awarded the Logan Medal of the arts and received a Guggenheim Fellowship in 1966. Feeling that he'd reached the end of his style's potential, he shifted in 1967 to black and white images that dealt with challenging perspectives and "spatial conundrums". Some critics dismissed this work as simply disorienting; others declared it Held's finest achievement to date. By the late 1970s, he had re-introduced colour to his work. In 1988 he was elected into the National Academy of Design as an Associate member, and became a full Academician in 1994. In his later years, Held earned commissions of up to one million dollars. In 2005, he completed a large, colourful mural in the New York City Subway system, at Lexington Avenue / 51st – 53rd Streets station. Three of Held's murals were in the original WTC 7 building. At age 76, Held was found dead in his villa swimming pool near Camerata, Italy, on July 27, 2005. It is believed he died of natural causes. Work Pigment paintings The most distinguishing part of Held's pigment paintings were the thick brush strokes of paint in random directions that are reminiscent of Abstract Expressionism. These strokes were short, gestural and are commonly referred to as action painting. The colors included earth tones that are muted and spread around chaotically. Typical for many of these paintings was no foreground or background and sections were splashed with drips. As time went forward in the fifties, Held began to lengthen his gestures and combined strokes into triangles, circles, and rectangles. This was alluding to the geometric abstractions that started at the end of 1959. Hard edge paintings During the late 1950s, gestural painting was something that Held had begun to lose interest in. He and a few other artists such as Morris Louis and Kenneth Noland felt a growing problem emerge. The style had brought a large number of mediocre artists and become overdone for them. By 1960 he had succeeded in finding an alternative method given the label hard edge. In other ways it has been described as post-painterly abstraction, new abstraction, and cool art. The famous exhibition organizer Irving Sandler has been known to characterize it as concrete expressionism. The development of this style also led Held to change his medium from oil to a water-based acrylic.