Louis Désiré Blanquart Evrard

Louis Désiré Blanquart-Evrard (2 August 1802, Lille – 28 April 1872, Lille) was a French cloth merchant by trade, but in the 1840s became a student of photography. He studied the Calotype process, and in 1847 became the first person to publish the process in France. He developed a method of bathing the paper in solutions of potassium iodide and silver nitrate rather than brushing these chemical baths on the surface.

In 1850, he developed and introduced the albumen paper printing technique, which became the staple process of the soon to be popular Carte de visite. In 1851 in Lille, France, with Hippolyte Fockedey, he started the Imprimerie Photographique, which was the first large scale printing company to employ a large number of employees. In the 1850s he was known for publishing other artists works, including John Stewart's views of the Pyrenees and Auguste Saltzmann's views of Jerusalem. His process for the calotype had the disadvantage of leaving a blank white sky and dark foreground, which led to artist manipulating and using multiple negatives to add clouds to the sky and make the foreground more distinct. The problem with these manipulations was that often the clouds were taken in the morning and the foreground was taken in the afternoon.