The most defining trademark of Bong's films are their sudden tone shifts (sometimes within scenes) between drama, darkness, and black or slapstick humor. During a TIFF Master Class at the 2017 Toronto International Film Festival, Bong claimed: "I'm never really conscious of the tone shifts or the comedy that I apply, I never think 'oh, the tone shifts at this point or it's funny at this point.' I'm never conscious of it during the filmmaking or screenwriting process." Bong also uses real filming locations or specially built sets in all his films as opposed to green screens, even to the extent of filming in Seoul's sewers for "The Host" (2006); "Memories of Murder" (2003) set a local record for the number of locations it utilized.