This term is also applied to printouts from computers. Many proofreaders use the following method to proofread. They mark errors that appear in the proof and return the marked proof for corrections. Later they will check the corrected proof against the copy. Some proofreaders work on information that is displayed on a computer and make the changes directly to the file.
Proofreaders sometimes use a second method of proofreading.
They work with a second person who is known as a copy holder. The copy holder follows the original copy word for word as the proofreader reads the proof aloud. The copy holder calls attention to differences between the proof and the copy. In other cases, the copy holder reads the original copy to the proofreader. Braille proofreaders check proofs of Braille transcriptions against original scripts to detect errors.