Edward Lear's decision to reproduce his illustrations using lithography was unusual; the process was still relatively unknown in England, and its artistic potential had not yet been explored. Lithography was invented in Munich in the 1790's by Alois Senefelder, but his work was not translated into English until 1819. In the 1820's, Charles Hullmandel published The Art of Drawing on Stone; his studio in London, where Lear made his prints, became the birthplace of lithography in England.

Lear may have been attracted to lithography for reasons of artistic integrity. Most ornithological illustrators of the time, including Audubon, hired professional engravers to reproduce their work. In this process, the original drawing or painting was twice compromised. Firstly, it was interpreted by a sensibility and a set of hands that were not the artist's own. Moreover, no matter how faithful to the artist's intentions the engraver might have been, the mechanics of the engraving process itself inevitably resulted in a line that differed from that of the original medium. In lithography, by contrast, the artist draws directly on the stone using familiar tools and media; the image produced is entirely his own.

It is probable that Lear’s decision to use lithography was also one of economic necessity. He was hard pressed for funds; he had hoped to finance the publication of The Psittacidae with the income from subscriptions, but he complained of his subscribers’ delinquency, and, consequently, his own difficulty in paying his bills. It is likely that he could not afford an engraver.