When sewing a project and you have layers and layers of fabric and interfacings that make it very difficult to put a pin through but you still need to hold in place? I have found the perfect solution for this problem. Metal paper holders. (I am not sure of the technical name for these holders)They come in all sizes, but the small ones work the best because you can position them where you want them. I am currently making the Travel Bag by Amy Butler, which also calls for piping. I have tried trimming out the heavy interfacing but it just makes the sewing process to unstable and the presser foot wants to slip off the fabric. I can't use pins they will just bend, so these metal paper holders work great.