Quick answer: Use sew-through buttons (the flat kind with 2 or 4 holes) for lightweight fabrics like shirts and blouses. Use shank buttons (which have a loop on the back instead of holes) for thick or structured fabrics like coats and jackets, where the raised shank leaves room for the heavy buttonhole layer to sit … Continue reading Sew-Through vs. Shank Buttons: Which One Should You Use?