Photograms: A photogram is a photographic image made (without a camera) by placing objects directly onto the surface of a photo-sensitive material such as photographic paper and then exposing it to light. The result is a silhouetted image varying in darkness based on the transparency of the objects used. The areas of the paper that have not received any light appear lighter, and areas that have received light appear darker, this is according to the laws of photosensitivity. The image obtained is hence a negative, and the effect is often quite similar to an X-Ray.