Age journalist Martin Flanagan wrote that Petty "re-invented the world as a vast scribbly machine with interlocking cogs and levers that connected people in wholly logical but unlikely ways.
On his return to Australia in 1961, he worked at first for The (Sydney) Daily Mirror, The Bulletin and The Australian before joining The Age in 1976.
In 1976, the animated film Leisure, of which he was the director, won an Academy Award for the producer Suzanne Baker (the first Australian woman to win an Oscar).
(The Age, 22 June 2004) Petty made a number of other award-winning animated films including Art, Australian History, Hearts and Minds and Karl Marx.
[5] Petty said in the foreword to Parallel Worlds that he was a humanist and socialist, mentioning visits to Nicaragua and Cuba in the early 1960s, and feeling the influence of Colin Wilson's The Outsider.