Whether you are a home dressmaker or a professional tailor, three "must haves" are a French Curve, Designer Ruler and a Dressmaker's Square.

 

A French Curve is used for altering patterns for perfect fit, including curves for neckline, armhole, sleeve cap, hipline, waistline and hemline.

A Designer Ruler is a grading ruler with 1/8" and 1/4" increments, together with a  fine metric scale.  It is wide enough to use with a rotary cutter.  Imperial & Metric.

A Dressmaker's Square is a 60cm x 36cm metric tool for pattern drafters and home dressmakers - the 90 degree angle is used to square up fabric prior to cutting; it also has seam allowance guides of 6mm, 12mm & 15mm whilst the curve is used for hemlines and waistlines.