After Pett was invalided out of the First World War, he studied art at Press Art School.

In 1932, he created the erotic Jane, initially modeled by his wife Mary but later with professional models. On 28 April 1936, Jane accidentally lost her clothes for the first time. This became increasingly common. At the time of the Second World War, Jane changed from being a daily humour strip to being a continuous story as a spy action-adventure series. Pett retired from drawing Jane after in 1948.

In 1948, Pett drew a comic adaptation of Warner Bros' The New Adventures of Don Juan (1948).

He then created Susie, another daily newspaper strip about a woman who frequently stripped, for the Sunday Dispatch. This series was regularly published in Australian in World's News.

Around 1950 the British Foreign Office secretly hired Pett and his writer-partner Don Freeman to adapt George Orwell's Animal Farm into a comic strip, as part of their anti-communist propaganda program. The 78-episode strip allegedly ran in Burma and Brazil, but not Britain. The work was declassified and became public in 1998.

Pett also contributed to Amalgamated Press weekly comics, including 'June' (1949) for Comet; 'Cardboard Cavalier' (1949) and final installments of 'The Captain from Castile' (1949) for Knock-Out; and 'Penny Wise' (1951) for Girl. 

He taught art at the Mosley Road Junior Art School and at Birmingham Central School of Art.