I’ve done this slightly differently. I iron on the freezer paper, then use chalk to rub over the edges, then pull up the paper. You get a negative image when you pull up the freezer paper and have no chance of stitching through the paper. You can chalk each one as you come to it, so the image lasts long enough to quilt. You can also add internal detail if you want with this method and reuse the templates a number of times.