Part of Cyril's artwork are originals by Mathias Cousin; the rest were done during filming by cast member Ugo Bienvenu.
In a 2015 interview with Hazlitt, Mia Hansen-Løve spoke about the commitment to accuracy in the film: "It was very important for me, and for my brother-it was, like, his obsession. For me it was very important, of course, but sometimes I would say, 'C'mon, we can't please everybody anyway, we just have to focus.' But Sven Hansen-Løve, and I think he was right to be stubborn, because it's his entire life, for him, it was so crucial that everything had to be true, authentic-the music, of course, but also the sets: we paid a lot of attention to the different clubs, and we tried to film at the right places, places where it actually happened. It was also very important for us to have the real people playing their own parts. The DJs and singers you see in the film, it's them: it's them my brother used to go to, and it's them who used to sing at these parties. It's them, fifteen years later than the real story, but they hadn't actually changed that much. It was crucial for us, symbolically, to have these people involved in the film. The other thing that was very important was to have that scene in Chicago, because for us it was the moment where we go to the very source, of where everything started. When we did the first editing of the film, and people saw it, some told us, 'It's too complicated in Paris, New York, and then Chicago. Why did it have to go to Chicago? Why don't you keep the scene but put it in New York?' But for us, it was very important. We couldn't imagine to have moved the scene from Chicago to New York. My brother always talked-when I was 15, when he started listening to garage music-it was always all about Chicago, and you would go to these guys, to these DJ producers, and you would go to them in Chicago just for one day, to listen to just one track, and that was something we needed to have in the film, if we made a film about garage music."