Large, rare example of Niépce de Saint-Victor’s heliogravure process.
Pauline Riffaut together with her husband produced many of the early French Heliogravures from 1853 to the early 1860s. She worked with Adolphe Pierre Riffaut (1821-1859) until his internment for madness and then by herself. Adolphe Riffaut was a noted engraver, etcher and printer. He was involved with Lemaître, Mante and Niépce de Saint-Victor. Madame Riffaut is singled out on a number of early plates with the imprint “Photographie sur acier par Mme Riffaut.” A portrait of Niépce de Saint-Victor bears the inscription “Photographie sur acier par Mme Riffaut d’après les procédés de Mr. N de St V.” There is at least one plate that was originally imprinted with Mante’s credit and then in a subsequent printing imprinted with her credit. Full authorship of these early heliogravures may never be sorted out. 
 Hanson, David Checklist of photomechanical processes and printing 1825-1910, 201 p. 132