In publishing, as a final step before actual printing takes place, after it has been edited, laid out, and designed, the proofreader searches for typographical and layout errors. The proofreader works with a facsimile of a finished product, or a proof (hence the term proofreading).
Proofreaders don’t suggest major changes to the text; instead, they look for minor text and formatting errors and confirm the material is ready for publication.
The proofreader’s job is to check for quality before the book goes into mass production. He or she takes the original edited copy and compares it to the proof, making sure that there are no omissions or missing pages. The proofreader corrects awkward word or page breaks.
While they may do light editing (such as correcting inconsistent spelling or hyphenations), the proofreader is not a copyeditor. If too many errors are cited, they may return the proof for further copyediting.
Traditional publishers require professional proofreading as a quality assurance measure before printing a mass quantity of books.
Self-publishing authors who have had their manuscript professionally copyedited often choose to skip the proofread. If you’re on a budget, you might try to correct your own work, since there won’t be as many errors to contend with at that stage. A word of caution, however. This is your final chance to get everything right before the final product is produced. Don’t waste the opportunity.
Check through the proof copy page by page, paying close attention to the layout in particular. You’ll be surprised at how small errors that may have slipped through all previous checks. Mistakes which could have been picked up easily by a thorough examination of the proof can undo all the work you’ve put into achieving a professional and high-quality final product.