This is a very important part of the printing process which must be checked properly before signing off on any print project. Proofs are done not only to make sure that the printer or bureau has output the file correctly, but to also ensure that you or your customer are happy with the results. At the time of writing, this topic is heavily influenced by the trend away from film reproduction and into CtP. With film reproduction, proofs could be made before plates were made, but certain methods such as DuPont Chromalin required film to be imaged first. CtP changes this entirely.