"Oh, how do you spell vinyl anyway?" he asked.
"The other way. " I said. "I know. I'm a professional proofreader."
Standing at another area of the counter was a guy waiting to have this job run out on an oversized plotter. The store clerk said to the guy that a customer had alerted him to the problem and it would have to be fixed. The other customer says, "OMG, how did I get that wrong?"
Wanna know where my business cards were? In the car. Anyway ... it as a fun exchange and I have the guy's number. I can call him with my business card info. For next time.