The term "contract proof" is defined as a proof that becomes a legal contract between the producer and the customer, once the customer has signed the proof. It must be understood by the customer that the proof does not represent the exact appearance of the press sheet. Proofing material is often brighter than what is used in the actual printing and it almost always has greater image density than a press can deliver. The contract proof only simulates and predicts the appearance of the final printed piece. It is used in the pressroom as a guide to compare colors while the piece is running on the press. A contract proof can be produced as:

• a photomechanical (analog) proof from the film
• a digital proof from a digital file
• a press sheet as a press proof