The term camera-ready was first used in the photo offset printing process, where the final layout of a document was attached to a "mechanical" or "paste up".
In this system, a final paste-up that needed no further changes or additions was ready to be photographed by the process camera and subsequently printed.
This artwork may have looked messy to the naked eye or to a modern consumer digital camera - covered in various pieces of paper attached with adhesive or wax and composited with white out, gouache, tape and blue pencil (non-reproducible) and red masking film, black or clay-based paint (reproducible as black) - but appeared perfectly uniform to the monochrome reproducing camera used for print reproduction.
In recent years, the use of paste-ups has been steadily replaced by desktop publishing software, which allows users to create entire document layouts on the computer.
In the meantime, many printers now use technology to take these digital files and create printing plates from them without use of a camera and negative.