Action painting
Ortman first exhibited in the Salon de Mai in Paris in 1950. Upon his return to New York City he was invited to join the Artist' Club, a meeting place for artists whose members included early proponents of Action painting and Color Field painting. In 1953 he had his first solo exhibition at the Tanager Gallery, one of the Tenth Street a co-operative galleries that together formed an avant-garde alternative to the more conservative 57th Street and Madison Avenue galleries. In 1954, he and actress Julie Bovasso founded the Tempo Playhouse to perform contemporary European playwrights, including the first American showings of Jean Genet, Eugène Ionesco, and Michel de Ghelderode.