You control your 1/4" seam. I use the 1/4" foot, but move the needle to the correct position to obtain a 'scant 1/4" seam allowance'. My machine (Janome 7700 Horizon) has a memory feature that stores my setting so I don't have to reset each time. Moving the needle (that is, changing the 'width' of the stitches while in straight stitch mode) allows you the flexibility you need to achieve 1/4" seam on any fabric.