A contact print is a print made by placing a negative directly on photographic paper and exposing it to light. Usually a sheet of glass presses the two together. The print is the same size as the negative, because there is no enlargement. A contact sheet is a contact print of a whole roll of film, cut into strips, on one sheet of paper. In a traditional darkroom, photographers make a contact sheet first. They study it to choose which frames to enlarge.
Do you have a better definition? Share it in the comments.
