Who is responsible for proof-reading and making sure there are no mistakes in the finished job?
Ultimately, you are. Keep photocopies of the work to check against the proofs you are given. Make all your alterations clearly in red ink and, if the changes are significant, say you want to see revised proofs before giving the go-ahead for printing. Check the proofs carefully and away from the hassle of the printer’s shop. Be clear about the priorities underlying proof-reading. If potential customers cannot contact you because a phone number or an email address is wrong, you lose business. If prices are missing or incorrect, you may miss out on sales or face other problems. If there are more general errors of fact or spelling mistakes, you may be able to ignore them, or you may find you have a brochure that is embarrassing and unusable. All these difficulties can be avoided by careful, concentrated, nit-picking work at the proofing stage. But remember, whatever mistakes the printer had made up to this point, they become your problem once you sign off the proofs.
