PP Puckering Has Me In A Pickle
I love PP and have been doing it for quite some time. All of a sudden I am getting a pucker on the back side of my seam. I am using a 90/14 needle, 50 wt thread, setting for 18 stitches per inch with bobbin tension set at 4. This combination has been my normal PP setting and has always worked just fine. I have cleaned all the parts, switched to a brand new needle, played with the bobbin tension and nothing works. If I do a practice stitch on two pieces of material the seam is straight and true, no puckering. I'm at a loss what I'm missing and why this started happening. Am working on a queen size quilt for an August wedding so I've got to figure this out. Any and all suggestions will be greatly appreciated. I also tried the same settings on my other machine and it does the same thing. The paper I'm using is foundation piecing paper. I'm completely baffled. Thanks for considering my predicament and all ideas will happily be tried.