I find removing the papers is easier if I start in the middle. Fold on the line, crease with fingernail. Hold by the seam allowance, place thumbnail in center of the block, pull the papers at the center, where your thumbnail is, then tear from the center to the corners. I hope that makes sense. By starting in the center, you don't pull the threads at the corner.
Also, using a smaller stitch length gives the seam more stability and helps it tear more easily.
Hope that helps.