Sending your work off to be printed is a little like sending your child to the first day of school. What should he bring? How should he dress? And does the school have your number in case of emergencies?
With a print job you have to know what kinds of materials the print shop requires. You need to anticipate problems that could develop. And you need a way for them to contact you with questions.
The best-laid schemes o’ mice and men Gang aft a-gley.