This lovingly curated documentary on the celebrity American author and social satirist Kurt Vonnegut had a long gestation. In production for decades, ever since filmmaker Bob B. Weide first approached the writer about making it, it developed at a leisurely pace as the writer provided an extensive archive of materials, including 16mm home movies of him as a child. During the lengthy production, the two men became close friends.

Weide, who co-directed with documentarian Don Argott for the big picture, says he felt as though he had become Vonnegut's archivist. It was clearly a special relationship, that even once included a collaboration on a screenplay on a Nick Nolte film. Though it was not a success, the adventure seemed over time to become something of a shared joke between them.

It is surprising that, besides this film, there is so little on screen dedicated to the career of one of the premier American writers of last century, who was published throughout his life. Vonnegut, of course, shot to best-seller prominence in 1969 with his novel Slaughterhouse-Five, the anti-war classic that resonated with the huge anti-Vietnam War protest movement of the time, and retained his position as a prominent social critic thereafter.

Since reading Breakfast of Champions at school, Weide had been an admirer of Vonnegut's work. As soon as he was established in the field, the 23-year-old aspiring filmmaker asked Vonnegut, who had turned 60, if he would agree to a doco being made about him. Vonnegut was happy to let this happen, and production maintained a leisurely pace, dragging on for years. Weide has mentioned that Vonnegut was delightfully indifferent to the project never getting a wrap. It says something of the writer, as does Vonnegut's loyalty to a filmmaker who was developing a track record in films about comedians.

Kurt Vonnegut: Unstuck in Time is a tribute to the access that Weide had to Vonnegut and his family and friends over the years until he died in 2007. The trust and friendship show in the results. There is footage of him at his first high school reunion, when his cohort recall friends who had died in Europe during World War II. And there is open access to two of his daughters who confirm their father was very at ease with filmmaker Weide.

Wit and dark humour are defining characteristics of Vonnegut the public figure that come through the rich fabric of clips from his guest-speaker events. Even if you haven't read many of his 14 novels or his short fiction collections or his essays or seen his plays, there is a wealth of memorable quotes to enjoy and mull over in the clips from his presentations, often to generations of young students.

From the baby brother inspired by Laurel and Hardy who played the clown to get attention, who felt he ought to be funny, he went on to become the wise old fool, pointing out the dangerous contradictions in life, and where his country had gone wrong.

Speaking to camera early on, Weide says it had never been his intention to appear, because he was against filmmakers making their presence felt. Here, there is quite a lot of the director in a film that is the natural outcome of the bond between writer-director and subject.

Fair enough, but I think Weide inserts a bit too much detail of his own life and marriage, distracting from the tremendous legacy that Vonnegut left behind. The film's title refers to the narrator in Vonnegut's semi-autobiographical novel, Slaughterhouse-Five, who experiences the Allied bombing of Dresden in 1945, surviving along with fellow prisoners-of-war in a slaughterhouse underground.

It is impossible to consider Vonnegut's work without taking into account his wartime experience as a young serviceman who knew little of life beyond the Midwest before he was delivered into the horrors of war-torn Europe. Such a definitive experience would shape a world view forever, but it is remarkable to hear from the man himself and his two daughters about how he coped thereafter. Those interviews are particularly revealing.

Over all those years, from pre-production to post, Weide was working on this on and off, with the thought that he would figure it out later. The film gained a lot from the process, and so have we.