From the outset, Leblanc wanted to go beyond the usual notion of Abstraction, whether lyrical, geometrical or constructivist, so as to concentrate all these sources in a new relationship between image and reality, between materials and light. The significance and quality of his creative achievements are art-historically recognised as a fertile and vital source of present and future creative generations. A co-founder of the G58 Hessenhuis, Leblanc associated with the ZERO group, with whom he participated in international exhibitions. Following his first one-man show at the Palais des Beaux-Arts, Brussels in 1961, Leblanc organised the exhibition 'Anti-Peinture', Hessenhuis, Antwerp in 1962 and became part of the international group 'Nouvelle Tendance'. In 1964, Leblanc won the prestigious prize Jeune Peinture Belge/Jonge Belgische Schilderkunst. During 1977, until his early death in 1986, Leblanc was teaching at the Instituut voor Architectuur en Stedenbouwkunde (NHIBS), Antwerp.

The work of Leblanc is in museum collections worldwide, including Centre Pompidou, Paris; Tate Modern, London; Museum Kunst Palast, Düsseldorf; Josef Albers Museum, Bottrop; Stedelijk Museum, Amsterdam; , S.M.A.K., Ghent; Mu.Zee, Ostend; Musée des Beaux Arts, Brussels.