A photogram is a photograph created without a camera. Instead it's made by taking photographic paper, placing objects on top of it, exposing it to light. Thus the photogram is white where the light was completely blocked, black where there was no object in the way of the light, and various greys where translucent objects blocked it's path.

Around 1918, photograms emerged as an art with the creation of photograms by Christian Schad (a member of the Dada movement who called his photograms Schadographs), and were used in the 1920s by photographers such as Man Ray (who called his Rayograms).

Pho"to*gram (?), n. [Photo- + -gram.]

A photograph.

© Webster 1913.