It's interesting that the article doesn't mention the use of bitumen in early photography and photoengraving. Bitumen hardens preferentially in areas that have

It's interesting that the article doesn't mention the use of bitumen in early photography and photoengraving. Bitumen hardens preferentially in areas that have been exposed to light. The very first photographs ever made were done on bitumen-coated plates. https://en.wikipedia.org/wiki/View_from_the_Window_at_Le_Gras https://en.wikipedia.org/wiki/View_from_the_Window_at_Le_Gra... "Faster" coatings were soon developed for camera use, but bitumen continued to be used to make photographically-reproduced printing plates for quite a long time (in that application, a long exposure time is not as critical, and may even be advantageous).