As with most anything, there is no set rule. Do what works for you. I happen to remove when I finish a block. I tried leaving the paper on with one of my doll quilts and had a dickens of a time getting all the litte bits of paper from in between the seams out. Yes, I used more stitches to the inch so the perforations made it easier to tear, but it was a mess at the seams. I am no expert and have not done a large PP quilt so my opinion is probably not worth the paper it is written on. :roll: