Well, you certainly received a lot of suggestions for a foundation for paper piecing. When I was teaching paper piecing I used vellium that I purchased from a neighborhood printer and after running the pattern through my printer, distributed a few sheets to the students. Vellium is easy to see through and you can remove it from the block easily. For personal use I use newspaper paper, purchased at an office supply store. Newspaper paper is thinner than vellium, but after cuting down to 8.5" x 11", it goes through the printer beautifully and is removed from the block quickly. For a complex block (New York Beauty or Mariner's Compass), I use non-fusible interfacing that remains in the quilt. You can also purchase Carol Doak's paper at Joann's (and use the 40% off coupon because it's a little pricy). Good luck with whatever you decide on.