The Betty B. Flat is a tool designed with quilters in mind,and is a step above any other conventional pressing method. The results are a seam that is much flatter and prevents seam allowance impressions. Keep your Betty B. Flat close by your pressing area. Press your seam as you normally would,immediately set the Betty B. Flat on the hot seam. Let your Betty B. Flat set for about 5 seconds now you have a perfectly flat seam!