I once sewed a heart "log cabin" quilt using a true 1/4". By the time I was sewing on the last couple of pieces in the block, they were always coming out too long. If I had used a quilters 1/4" foot, I would not have had that problem. It gives you a scant 1/4" because by the time you press your seam you are using up the last part of the true 1/4" allowance.