Disintegration of the artistic environment and the political atmosphere in the country prompted Kossakowski to emigrate to France in 1970. He worked i.e. in the Museum of Decorative Arts in Paris and the Pompidou Centre. He cooperated with French magazines and publishing houses. He also started to pursue conceptual photography. He gained recognition with his series 6 Metres Before Paris (6 metrów przed Paryżem), presenting “Paris” road signs on the roads accessing the city, along with their suburban surroundings.
Other noteworthy series are the photographs of the patches of light, created by the stained glass windows in the Chartres gothic cathedral.