[3][4] Today, Kupczynski's works are held in private and corporate collections worldwide, including the estates of former US President Richard Nixon and Pope John Paul II.

[7] At the age of 11, Kupczynski escaped to Warsaw with his mother during the Soviet invasion of Poland, while his father went to the United Kingdom to aid in the war effort.

[9] Described as "one of the wild boys of Polish art" by Harold Schonberg of The New York Times, many of Kupczynski's portrait paintings are characterised by his unique personal style, use of bright colors on canvas, and trademark mini-scenes on the accentuated noses of his subjects.

In 1952, Kupczynski became a member of The Association of Polish Artists, but the country's socialist realism policy barred his work from exhibition due to his tendencies towards expressionism and semi-abstract art.

By the late 1950s, Kupczynski had attracted the attention of both Polish and Western critics, and he was featured in various publications, including Tygodnik, Stolica, Przeglad Kulturalny, Wspolczesnosc, Po Prostu, Munchen Merkur, and Tagebuch.

He was one of three artists featured in a documentary by The National Film Board in Poland, and he was awarded a government grant that enabled him to continue training in Paris.

In 1962, Kupczynski initiated the first outdoor modern art exhibition in Warsaw on the walls of Barbican in Kraków, evoking provocative cultural and political dialogue between artists and the hostile communist regime.