Kubert's first known professional job was penciling and inking the six-page story "Black-Out", starring the character Volton, in Holyoke Publishing's Catman Comics #8 (March 1942; also listed as vol.
Kubert's first work for DC Comics, where he would spend much of his career and produce some of his most notable art, was penciling and inking the 50-page "Seven Soldiers of Victory" superhero-team story in Leading Comics #8 (Fall 1943), published by a DC predecessor company, All-American Publications.