Blackman, born 12 August 1928 in Sydney, left school at 13 and worked as an illustrator with "The Sun" newspaper while attending night classes at East Sydney Technical College (1943–46) though was principally self-taught. He was later awarded an honorary doctorate. He came to notice following his move to Melbourne in the mid-1940s, where he became friends with Joy Hester, John Perceval and Laurence Hope as well as gaining the support of critic and art patron John Reed. His work met critical acclaim through his early "Schoolgirl" and "Alice" series, the latter Blackman's conception of Lewis Carroll's most famous character. For some time while painting the Alice series, Blackman worked as a cook at a café run by art dealer Georges Mora and his wife, fellow artist Mirka Mora.