That's what I've been using Stable Stuff. I order it from Ricky Tims website. It is sold by the 3 yard bundle or by sheets of 50. I decided if I'm going to sew on paper I'm not going to use something that makes extra work for myself just because it's cheap or free.

I don't think that leaving foundation papers in a quilt is a good idea once the top is completed because of a myriad of possible problems. I haven't done much paper piecing lately, but when I do, I usually sit and tear out the paper while watching TV at night, as it's sort of a mindless effort to do so. I just wouldn't want to take the chance of problems that could arise from leaving the paper in.

Ok, Now I have done lots of quilts with the paper left in...from newspaper to tissue paper. It does not act like a bit of Kleenex left in the pocket. It does not wad up. It just sort of melts into the batting and IS NOT AT ALL NOTICEABLE.
Good gracious if you are at all concerned then just make a sample up and wash it. No need to buy an expensive product when old phone books are still available. Take it from someone who's first quilt was a crazy quilt pieced on newspaper, washed in wringer washer and still won a ribbon at the county fair.

There is wash-away paper available.

I care too much for my pipes and septic system to try that.

That is what I do. I can stitch a stack of the papers at one time. Use the one from the back of the stack first as they are stacked because of the stitching. I know that doesn't make sense but it would if you would do this and look at it. :)

I use calculator tape or paper piecing paper but set my stitches very tiny and it pulls away easy. Hate removing it but I would not leave it in. That's my opinion.

Once upon a time in a faraway place, I used the disolvable fuseable paper for a baby quilt. You are supposed to wash it out when you are done. Duh, I think they mean before you quilt it and bind it. I had these horrible Gobs of what seemed to me like paper mache glue. It was a disaster. Took nearly 6 washes and I was still not sure it was all out of there. I would NEVER forget to take off paper from paper piecing after that.

Anyone know if the Ricky Tims Stable STuff can be used in a printer for printing paper piecing patterns?

I love PP but totally hate tearing the papers off after the blocks are done. My cure to this problem was to use a thin interfacing as my foundation. It can be left in and does not add bulk to your quilts. I think it is on sale right now at Joann's for 49 cents a yard. I buy it by the bolt when it is on sale.