A straight stitch foot is useful when sewing fine, heavy, textured fabric or when topstitching.
 
On fine fabric it helps to prevent skipped and puckering stitches and helps to stop fabric from being taken down into the bobbin area.
 
For topstitching or seaming on a textured fabric such as a drill, twill or slubby fabric such as silk dupion.
 
Gives an accurate straight stitch.