Anyway, you're not comparing the same kinda stuff. When someone is sending you a ton of copy for offset printing, whether it be magazines, brochures or major documents, of course you need a waiver to protect your self, but what most here are talking about are
signs. Most of them don't have but 5 or 6 words up to maybe a dozen or two. If you can't look at your files and see something is spelled wrong, that you're just not qualified to be in that department. You should be pushing a broom or digging holes if you can't spell.
Even the smallest jobs should have a simple signoff, it's not hard and it's standard throughout the print industry.
Sign shops just seem to have weird blind spots about some of these things, see all the discussions about copyright, art ownership, charging for design...a lot of reinventing the wheel. A small paragraph with a "
sign here" line on your proof or job approval sheets, no big deal, will save you a ton of headaches.
You should especially have
sign off when you're doing the design, you have a proofing process right? At some point you need to define the design as final, at that point the final signoff should be
final--that includes spelling. The design is frozen at that point. Any reasonable person will understand that, and it gives you ground and professional options for dealing with an error that will usually result in everyone happy. Otherwise it's just nebulous and you're going to eat it every time, which isn't a great way to run a business if you have a goal of ever turning profit. This is how freelance designers and design agencies handle signoff, why wouldn't you also handle it that way if you're doing design for a client? Doesn't make any sense to avoid having a signoff process.