WHile I have always understood more or less how an all lace piece is made, I have always wanted to know how they make a piece with a PSB or skin perimeter. I mean, do they make the lace part and the PSB part separately and then attach the two? And how are they attached? I have been trying to come up with a way to add a PSB-like material after the fact to very selected spots on an all lace piece so that I can get the best of both worlds without having to experience a change in ventilation like there is on a factory made PSB perimeter. I have some ideas, but I need more info on how the factory does this. I don't think I'm asking for secret info because all the factories seem to make a lace unit with a skin perimeter.