Painter, genre painter, history painter, draughtsman, commercial artist, etcher, copperplate engraver and illustrator
Eisen's artistic beginnings are in many respects comparable to those of Cochin. His training under his father François and especially his teaching and activity in the workshop of Philipp Le Bas laid the foundations for his later success as a draughtsman, crowned by his appointment as 'Dessinateur du Roi' in 1776. That he also gave drawing instruction to Madame de Pompadour speaks for his high regard.
Eisen's erratic lifestyle appears to have led to his exclusion from the Académie Royale; instead, he became a member of the Académie de Saint-Luc, in whose salons he regularly showed his paintings. But his most important activity was illustrating books. Together with Cochin and in collaboration with Le Bas, he helped to make book illustration an independent art, for their drawings were no longer mere designs meant to break up the text, but rather autonomous, imaginative pictorial statements. This surely contributed to the popularity and dissemination of such works. Eisen's best-known illustrations were the designs for La Fontaine's 'Contes et Nouvelles', which appeared in 1762. Despite a large number of surviving paintings, his work as a painter has largely been forgotten.