Hello fellow analogers. I have metal femomasks and I want to file them down a bit on the edges so that the negative borders appears in the print and I get a nice bit of diffusion fall off to white (ie no, i do n't want to use a larger masks and have perfectly straight edges). Before I butcher my enlarger, does anyone have any tips such as what kind of file to use etc? Any help would be greatly appreciated. And happy New Year everyone, stear clear of the megapixel in 2007!