The work of Petitjean is influenced predominantly by that of Signac and Neo-impressionism and comprises of two main subjects, the representation of the landscape and the Arcadian . It is the depiction of the Arcadian which links him to the art of Puvis de Chavannes of whom he was an early advocate.
Petitjean upon completing his academic work adopted the pointillist technique. This technique was founded by Seurat and Signac in 1884 at the Salon des Independants. through their desire to achieve a greater purity and luminosity of colour than could be achieved by just mixing pigments The idea of placing dots of pure colour side by side was developed from the theories of the scientist Chevreul. Seurat and Signac realised that this contrast of colour gave great luminosity.
He participated in the 1891 salon and was in 1892 to show his work with the Neo-Impressionists. Petitjean’s work between 1890 and 1895 reflects most strongly the Neo-impressionist technique and Spirit.
His pencil drawings are said to be reminiscent of those of Seurat. Whist his compositions with their gentle colours reflect the work of Fontin –Latour and Puvis de Chavannes.
After 1912 his work becomes fresh and spontaneous and more reflective of Pointillist watercolours.
In 1955 a retrospective of Hippolyte’s work was organised by the Paris Institute.