Sewing Machine Seam Guide - QPGUIDE. This tool is great if you are switching between sewing machines to make sure you get an exact 1/4" or whatever seam allowance you need..  Align your sewing machines's needle simply & easily by placing the guide under the machine's foot with ruler side edge along right edge of foot. Adjust needle so when it is lowered, it goes through the hole for the seam size you want. The mitered end is handy for piecing binding strips.