The final step in the editing process.
You’re done with revisions: POV is consistent, verbs are verbing, and your character is wearing a blue windbreaker—because the trademark on Windbreaker has expired and we don’t need that dorky capital W in the middle of a perfectly good sentence. (Yes, that’s the kind of thing your copyeditor thinks about.)
Now it’s time for quality control. When proofreading, I use the style sheet created by the copyeditor to double-check the proofs of the final copyedited manuscript. At this point, all editorial decisions have already been made, and I am reading for typos, dropped text, formatting issues, and other glaring errors.
Because the crucial benefits of a proofread are best delivered by a fresh set of eyes, I offer proofreading only for books that I haven’t already copyedited. I’m happy to recommend a qualified proofreader for manuscripts I’ve copyedited.