Seams Sew Easy! Seam Guide by Lori Holt for Riley Blake - STSEAMGUIDE - specify: Red, Aqua, Pink or Green lines. Lori Holt designed her Seams Sew Easy? Seam Guide for an accurate 1/4" seam and for constructing easy corner triangles. This tool saves time by not having to mark lines on your fabric when sewing half square triangles, flying geese or snowballs. The center circle of the guide is also marked with 1/2" grid lines for a wider seam allowance. This is a seam guide that temporarily adheres to the bed of any sewing machine. These grid lines also help to ensure correct placement when adhering to your sewing machine bed