Katz was born in Karlsruhe in 1892. In 1912 he visited Henri Matisse's studio for a few weeks. From 1913 to 1918 Katz studied art, first at the Karlsruhe academy, and then in Munich. He married and moved to Frankfurt, where in 1920 he published the "Danse macabre", a series of expressionist lithographs which alluded to the German Revolution of 1918–1919. Katz's work, which consisted of portraits, cityscapes, and still lifes, was influenced by Max Beckmann and the New Objectivity ("Neue Sachlichkeit") movement.