Not only did the barber chair joke become the climax of the cartoon. In an August 4, 1975 interview by Donald Ault and Thomas Andrae, Barks has said it was "the gag that caused Walt and the others to think they could get enough material to make a picture on that subject." Disney assigned Barks to write a script for the story in collaboration with Jack King, who was appointed director. (Jack King was brought over from the Warner Bros cartoon factory, and he would later direct most of the Donald shorts on which Barks worked as storyman.) Barks drew the storyboards. In November 13, 1987 notes, he wrote: "I was the lowly apprentice at this early date in the story department. Naturally I had to do most of the drawing work."
At this time, Barks had his first conference with Walt Disney. In 1936, Walt was still "one of the boys" (in Barks' words); he would drop by the office to talk with the storymen and make informal suggestions for improving their work. After "Modern Inventions" Barks saw Disney only in formal conferences, after the storyboards for a cartoon were already prepared. Burdened with work on the feature films, and with expanded production of the shorts, Disney no longer had time for casual chats.
Barks: "He was in the building and just dropped in to see how Jack King and I were progressing. He stayed about an hour and seemed quite enthusiastic about the situations we'd developed for Donald. He and King were long-time friends from the early days of animation." (April 29, 1987 notes written for the Carl Barks Library)
An expert storyman in his own right, Disney made a significant contribution to the cartoon: "he suggested that the barber chair be a very talkative machine, like some human barbers." Walt also soothed certain anxieties Barks had about the sequence. In a May 29, 1973 interview by Donald Ault, Barks told: "Jack King and I were scared to death we were getting too risquè with this gag. But Walt said, 'Oh no! Part his hair right down the middle and by all means use hot towels to make him glow.' The towel gag was one of my original jokes, but I only wanted enough heat to make the duck uncomfortable. Walt wanted his fanny to be glowing red. He could see the visual possibilities."
Disney films often used what the animators called butt jokes. Barks' concern seems to have been not the substance of the joke, but the emphasis placed on Donald's lower anatomy by the bright red coloring and by parting his tailfeathers down the middle.
«Modern Inventions» (like «Donald and Pluto» and «Don Donald» before it), was released as a Mickey Mouse short; that is, the title credits originally read: "Walt Disney's MICKEY MOUSE Presents", with Mickey's name larger than the title. Donald was not yet a box office name, so it made sense to have his famous colleague introduce him. «Modern Inventions» changed that; it was the cartoon that made Donald a star, and it was a Barks gag that made the cartoon.
Initially, the cartoon was to have been called "Mickey's Inventions" and would have starred Mickey and Donald. A 1936 model sheet with this title also shows that the robot butler which keeps taking Donald's hat had been invented before Barks became involved with the film. A later sheet featuring only poses of Donald modeling various hats, bears the title «Modern Inventions». It is likely that the storymen were in doubt for some time whether to feature Mickey or Donald, and Barks' gag tipped the scales. In the next few years, many films that began as Mickey shorts ended up starring Donald because the plots were deemed unsuitable for the mouse. Mickey had become a heroic boy scout who could not sustain the comic abuse that Donald might.
In an August 4, 1975 interview with Donald Ault and Thomas Andrae, Barks has told: "Up to 'Modern Inventions', Donald had been a firebrand and a rather silly character. Jack King and I made him a mischievous, sly-looking son-of-a-gun. We made him a more well-rounded character that could be used in more situations."