It was during Rembrandt's Leiden period (1625–1631) that Lastman's influence was most prominent. It is also likely that at this time Lievens had a strong impact on his work as well. Paintings were rather small, but rich in details (for example, in costumes and jewelry). Religious and allegorical themes were favored, as were tronies. In 1626 Rembrandt produced his first etchings, the wide dissemination of which would largely account for his international fame. In 1629 he completed "Judas Repentant, Returning the Pieces of Silver" and "The Artist in His Studio", works that evidence his interest in the handling of light and variety of paint application, and constitute the first major progress in his development as a painter.