He developed such a glowing reputation as an artist in Paris that the Academy soon offered to take him on as a member, provided he produced a new, quality work for his application piece.
Clemens left Paris in 1777 along with Jens Juel and Simon Malgo, and traveled to Geneva, where he made vignettes for Charles Bonnet's "Oeuvres d'histoire naturelle et de philosophie " and an etching based on Jens Juel's portrait of Bonnet.