I had a cathartic experience not long after having set up my own practice.
My client, a confectionery business were taking their first steps into new flexible packaging print (as was I). This was going to be six colour gravure which was exceptionally expensive and the print was bought in rolls by wieght (250 kilo rolls I seem to remember) so you can imagine how many sweet bags that would be.
My client (the MD) his production guy and I toured the prospective printers and once shortlisted we visited the chosen one again. This was my first time producing artwork for flexible packaging and I (making sure that my clients were there) impressed upon the printer's rep that he knew that and that I'd need my hand holding in every step of the process.
I duly prepared the artwork and asked the printer to be extra vigilant. I got a phone call from the client saying that that they'd got the bagging machine prepared and that the print was unusable - I thought I was going to be sick, we were talking thousands of pounds here. It turned out that there should have been a clear patch left when the bags were formed into a 'tube' so the adhesive could stick. I hadn't been told about it and the printers didn't notice either at repro or print stage.
Thank goodness that the client stood by me, having heard my conversation with the printers. However the production guy at the stweet company overcame it by making the packing machine work in a different way by offering two unprinted surfaces together rather than overlapping and saving the day.
The printer wasn't very helpful, but they lost out in the long run (forgive the unintentional pun) because these first two products were listed by a major supermarket chain and my client subsequently had his entire range repackaged and we used another printer.