just like you can get cotton gauze and cotton tarps, silk fabric runs the gamut. There is silk that is washable, but sometimes it looses its sheen. Since this is going to be an investment, I would buy small amounts of a couple different types and do some experimentation. Most (but not all) silk will water spot, frays easily, and most important, shows pin marks. From my garment construction days, I know you need to pin in the seam allowance only. If you sew something wrong, it is not very forgiving and you may need to cut another piece. Use silk pins, needles and if possible silk thread. I currently have a huge pile of mens' silk aloha shirts that I'm going to make a scrap quilt out of. I'm going to use a low heat stablizer (misty fuse) on the fabric before cutting. Good luck and would love to see your finished quilt!