Beginning in the mid 1860s with this publication, and lasting until the early 1880s, Édouard Baldus’ primary commercial activity centered on the production of photogravures, a process he first explored in 1854. This plate is the title page of his first major publication in gravure. It was a series of 100 heliogravures published between 1866 and 1869 reproducing ornamental engravings of past masters including Dürer, Ducerceau, and Holbein. This work had nothing to do with promoting artistic photography or his own photographic work; instead it was an industrial application of photography that brought credit and financial gain to Baldus as an inventor and entrepreneur rather than an artist. It was printed by Delatre.
"I here present artists and amateurs the result of long and and patient research, which has led me to the making of identical reproductions of old engravings using my photographic process. This process fixes the object immediately onto copper and carves it; it thus permits the multiplication of prints which are entirely similar to the original engravings. I call this result, or which I am the inventor, héliogravure." 
Originally trained as a painter and having also worked as a draughtsman and lithographer before switching to photography in 1849, Baldus became a central figure in the early development of French photography. Baldus was acknowledged in his day as a pioneer in the still-experimental field and was widely acclaimed both for his aesthetic sensitivity and for his technical prowess. Establishing a new mode of representing architecture and describing the emerging modern landscape with magnificent authority, he enjoyed high patronage in the 1850s and 1860s. Baldus made his reputation with views of the monuments of Paris and the south of France, with dramatic landscapes of the Auvergne, with photographs of the New Louvre, and with a poignant record of the devastating floods of 1856. 
Kate-Addleman-Frankel, After Photography?, The Photogravures of Edouard Baldus Reconsidered, Rijksmuseum, Amsterdam, 2018, pg 10
 Kate-Addleman-Frankel, After Photography, The Photogravures of Edouard Baldus Reconsidered, Rijksmuseum, Amsterdam, 2018
 MET www.metmuseum.org/toah/hd/bald/hd_bald.htm cited 02/22/23