I have a concern with using the dryer sheets as the foundation in pieced squares. Occasionally I have noticed little oily spots left on solid colors where there has been a dryer sheet in the batch. So when someone mentioned using the squares in foundation piecing. I immediately thought about the oil residue. So I took a dryer sheet that had been run through the dryer once with a batch of clothes. I pressed it with a hot iron over a brown paper bag. Oil stains. Moved it to another area of the bag. More oil stains. 3 times, 4 times.
Any comments on this? I would not want to stain my quilt blocks.