[1][2] He soon became close friends with Hugh Harman, with whom he attempted to do a series of Arabian Nights-inspired cartoons after Disney left for Hollywood in the wake of the bankruptcy of his original studio before rejoining him in 1923 to work in his Alice Comedies.

Soon thereafter, Harman-Ising Pictures gained a contract with Leon Schlesinger at Warner Bros. to produce cartoons beginning with 1930's Sinkin' in the Bathtub, which launched the Looney Tunes series.

Budgetary disagreements severed Harman-Ising Pictures' relationship with Schlesinger by 1933, after which the company outsourced a number of cartoons for Van Beuren Studios.

MGM fired Harman and Ising in 1937 over money disputes, only to hire them back the following year after the failure of its in-house studio's first projects.

Among those who worked in his unit were George Gordon, Mexican cartoonist Gus Arriola, Jerry Brewer, Bob Allen, and a recently-formed duo of animators, William Hanna and Joseph Barbera, whose first directoral foray, 1940's Puss Gets the Boot, which introduced the cat-and-mouse pair later known as Tom and Jerry, featured Ising as producer (being the only credited person in the short).