Quite often small errors in print jobs can cost the client or even the printer precious time and money.
To avoid that is as simple as making sure that your work is properly proofread and that a press proof has been approved. This ensures that you get the quality that is expected. Sometimes a fresh set of eyes can make a huge difference. Simply scanning through artwork, be it as simple as a one-page, a brochure or even a book, can cost you unnecessary time loss. Take the time to go through your work properly.