Kurt Cobain: Montage of Heck (2015) took filmmaker Brett Morgen eight years to make. Six of those years were spent acquiring the rights to everything necessary. When he finally gained access to the storage unit containing all of Cobain’s personal journals, tapes, and guitars, he was greeted with more stuff than he ever imagined.

As he told Indiewire, “I wasn't expecting that at all, in fact, that conversation had never come up [while negotiating access with the Cobain estate]-- [around] what sort of audio might be in storage. So we went and got two pro-tool systems to start transferring, and because I'm an archivist by nature, I don't skip over anything. I wanted to examine every little moment and that became really important, because Kurt was very careless with his audio cassettes; he would tape over stuff, he might start recording in the middle of a tape, or what-have-you.”

One of those tapes, released on the internet in late 2014, was titled “Montage of Heck,” and was a collection of noises, songs, and audio samples compiled with a 4-track cassette recorder. Morgen also found it to be a perfect representation of the man himself, and a blueprint for the documentary that shares its name and pairs video footage with original animations of the late singer’s journal entries.

Montage of Heck employs both single cell and motion graphic animations. Stefan Nadelman, the Portland-based animator and filmmaker, handled the motion graphic animation of all of Cobain’s artwork and journal entries.

“Each motion graphics sequence was built from still photographs that look straight down on pages from Cobain's journals. The resulting full-frame photograph provided Nadelman with the means to manipulate the angle, grain, light and texture so that the image felt just as analogue as the accompanying audio.” - Indiewire

The film also includes two cell animated sequences that illustrate audio tapes Morgen found in the storage unit. Though he didn’t originally intend to do audio illustrations, after discovering the Montage of Heck tape and another tape where Cobain told the story of his first sexual encounter and attempted suicide, tapes even Cobain's biographer Charles R. Cross didn't know existed, Morgen knew they had to be included in the film. Animating them was the only way to make that happen. After discovering animator Hisko Hulsing’s short film Junkyard (2012), Morgen employed him to illustrate the two segments of his documentary.

“"What I liked about Hisko was his art, his style was a 180 degrees from Kurt Cobain's style," said Morgen, "so it would never be confused as a self-portrait." To construct each sequence, Hulsing hand painted giant four-foot-by-six-foot canvas backgrounds using oil paint and shot real actors as reference points for his drawings.” - Indiewire

“From his small studio in Amsterdam, Hulsing compiled a team of 27 people (18 of them animators) and for four months they worked on not only the Cobain audio story, but also on the other portion of the film Hulsing was responsible for. For the 85 shots that were Hulsing's responsibility, they produced 6,000 animations and 60 oil paintings on canvas. Some of those canvas paintings were as large as six feet.” - Business Insider