He then started to study with other experts: engraving with Giovanni Volpato, landscape painting under the German Jacob Philipp Hackert and his brother Georg and architecture under Pierre-Adrien Pâris.
In this he was part of a group of engravers which collaborated with Benedetto Mori and the architect Augusto Rosa, considered the inventor of felloplastica, the art of constructing scale models of ancient monuments in cork.
Piranesi managed to steal Armfelt's letters which he had stored in the British embassy in Florence before beginning his work as foreign ambassador to the Kingdom of the Two Sicilies.
They opened a new branch of the family enterprise there, called Piranesi Frères, which decorated a line of terracotta vases manufactured in imitation of the ancient Etruscan works by Joseph Bonaparte.
The Emperor Napoleon came to his help, issuing an imperial decree granting the sum of 300,000 French francs, upon the condition that Piranesi dedicate himself solely to his engraving work, then considered the best in Europe.