His talent brought him recognition from several artists and opened the way towards Paris where during many visits he studied etching aquafortis with Bracquemond and Jacquemart. He had soon mastered all etching techniques, in particular soft etching, dry point and aquatint.

He frequented the Société des Aquafortistes (Etching Society) and during his return visits to Belgium, he founded the "Royal Nautical Club of the Sambre and Meuse" in Namur.

In 1864, he created a lithography of "L'enterrement en pays wallon" (funeral in Wallonia) which shows his sensitivity to the suffering of his fellowmen. It was during this time that he met Charles Baudelaire in Namur, thanks to the intervention of the editor Poulet-Malassis. The link between these two artists remained a strong one: Rops created the frontispiece for "Epaves", the condemned poems from "The Flowers of Evil".

In 1868 he was actively involved in the foundation of the Société Libre des Beaux-Arts in Brussels, of which he became the vice-president.

In 1869 he founded the Société Internationale des Aquafortistes (International Etching Society) in Brussels.