The first quilt I pp was a Storm at Sea and I left the papers in until the quilt was all put together--never again!! Now, this is just my very humble opinion, but there was more stress put on the blocks/bias edges trying to remove the papers from a whole quilt. The next 7 or 8 quilts I pp I removed the paper after completing each block--much easier, and much less stress on the blocks themselves. I either place them on my design wall or store flat in a plastic box so the blocks aren't handled that much. (I also think trying to get each and every tiny little piece of paper from the seams and star points can cause stitches to pull loose so I don't stress over those.). I know the "pros" or instructors advise leaving the paper on until the quilt is put together but why? When doing regular piecing, the blocks aren't supported by papers so I don't see a reason to leave them on when pp. Again, just a humble opinion--there's no right or wrong way.