Can anyone inform me please, do you file the inside of the bezel when you set a cabachon. In the school I went to they said you made it like a knife edge by filing the top of the inside of the bezel, all the ones I do that with look as if I have chewed it. I use proper bezel silver, I have thought about using sterling in .3mm instead to see if its a bit better, when I have filed it flat on the top it looks ok, but its not like a knife edge then. I am trying to save up to book a week or so in the Cornish School of Jewellery to learn the finer points of doing stuff, as the course I went on was very basic.