According an early pre-production news item in FD, Boris Karloff was first considered for the lead, and Cyril Gardner was first considered as director. A news item in HR reported that Chester Morris was also considered for the lead, but declined after deciding the role was unsuitable for him. A LAEx news item noted that Paul Lukas was also considered for a role in the film. According to a Jun 1932 news item in Var, "after several months on the script, Universal called off The Invisible Man," but offered no further explanation. An article in NYT revealed that in order for Claude Rains to "disappear" on the screen, a head and body cast were made, from which a mask was constructed. "When photographed in the mask against a specially prepared background, he became invisible." Further treatment of the film by John Fulton at a laboratory completed the effect. Scenes in which objects appear to fly through the air were achieved by using wires. HR also notes that production was interrupted on 15 Aug 1933 when a fire, started by a smudge pot kicked into some hay, burned an exterior set. A NYT article noted that at a dinner held in honor of the film, author H. G. Wells "remarked that while he liked the picture he had one grave fault to find with it. It had taken his brilliant scientist and changed him into a lunatic, a liberty he could not condone." According to the article, director James Whale responded that the filmmakers felt that they had to appeal to the "rationally minded motion picture audience," because "in the minds of rational people only a lunatic would want to make himself invisible anyway."
       A modern source includes Dwight Frye (Reporter), John Carradine (Informer), John Merivale (Boy), Walter Brennan (Man with bicycle) and Jameson Thomas (Doctor) in the cast. Other Universal films about invisibility are the 1940 sequel The Invisible Man Returns (see below); the 1940 The Invisible Woman (see below); the 1942 The Invisible Agent, directed by Edward L. Marin and starring Ilona Massey, Jon Hall and Peter Lorre; The Invisible Man's Revenge, a 1944 film directed by Ford Beebe and starring John Hall and Alan Curtis; and Abbott and Costello Meet the Invisible Man, a 1951 production directed by Charles Lamont and starring Bud Abbott and Lou Costello.