Photomechanical prints, usually illustrations, characterised by having tonal gradation simulated by a pattern of small dots that vary in size. They are typically printed from a block in which the tones were broken up into dots of various sizes by the interposition of a glass screen, ruled with fine cross-lines, between the camera and the object, usually another photograph. (Project Fotografie) https://data.cultureelerfgoed.nl/term/id/cht/9a87affe-636f-4376-808f-abe9397e3f75