I remember that after being in Thailand for about 5 years I was helping a Thai friend who was a manager of a gym. He had several thousand leaflets printed advertising the gym. He gave me some so I could distribute them...but I immediately saw a glaring mistake... a word with a double vowel '...าา'. I thought 'this is not going to go down well'. Having showed him the mistake, First he thought it might be just one or two leaflets but each bundle was the same. He was furious. He sacked the two individuals who 'designed' the ad because they obviously hadn't checked finished examples. He told them who had found the mistake and as they left, well if looks could kill. I went to the print shop with him where there was a big argument because the shop claimed that the proof had been accepted. In all I found four mistakes, the others being words with missing vowels. The manager of the shop was not pleased with me because he said that I probably influenced my friend to demand corrections free of charge, which of course I hadn't. I think I learned about the value of Thai 'loss of face' on that day.