The contact sheet (also called contract proof) is a positive print of all the negative images from a roll of 35mm film or medium format film. Contact sheets are typically made to allow the photographer to view a mini-preview of all the film to determine which photographs are best to print. Photographers viewing a contact sheet will often use a loupe – a type of magnification device to see small details more closely.
Printing a contact sheet is very similar to a contact print. You simply place the strips of film emulsion side down on a piece of photographic paper, ensuring everything lays flat, and expose the paper. 35mm film should be cut into strips of 5 or 6 frames, and medium format film into strips of 3 or 4 frames. You can either carefully place the negative directly on the paper, or you can place the film in an 8 x 10 inch protective, transparent film sleeve and place the entire sleeve on your paper. Making a contact print while the negative is held in a film sleeve is not generally recommended, but because the contact sheet is for proofing purposes only it will be fine. Before exposing the paper, ensure the negatives are free of dust or dirt.
While a contact sheet is used for proofing purposes, you can create test strip to determine the best exposure time. As you become more familiar with the darkroom and printing process, you will be able to create a good enough contact sheet for proofing purposes without the need to create a test strip in advance.