This folding ruler from Fiskars is perfect for dressmaking projects. Crafted from a durable 3mm thick acrylic, this ruler is ideal for squaring off corners and cutting triangles and squares from one to eight inches, this 8 x 8 inch ruler folds diagonally into a triangle for added versatility. The 1/4 seam allowance makes adding seams easy whilst the clear line intersections enhance visibility. Markings can be read on light, dark and patterned fabrics.