I use both the newsprint in the Judy Niemeyer's patterns or copy paper when the newsprint is not included. I don't have that problem when I am sewing anything unless my thread is hanging up. Meaning, it won't unwind without getting stuck in one of my thread guides. Did you try sewing on two other pieces of material to see if the machine will sew on regular material with the thread you are using for the paper piecing and make a good seam? Some threads are wound so that they have to be sideways to unroll correctly. If you are loading the thread sideways, could it be hanging up on the little notch that is used to secure the thread when you aren't using it? I tend to use larger cones which are 5,000 meters of thread and have to use a separate way to load the thread. Sometimes this can cause hanging up, then releasing, which makes the seams pucker.
This shouldn't matter, but I use a seam length of 1.6 when paper piecing. Although I love the better pressing of steam, I NEVER use steam anymore. I have had all types of puckers and stretching when I use steam. Now, I set my iron on the hottest setting - linen - and make sure I don't leave it on the material too long.
Last edited by Barb in Louisiana; 06-10-2015 at 05:03 AM.