This Clover #7811 Hot Ruler is perfect to measure, mark, fold, press deep hems, press long hems and mitre corners. It is heat resistant and you can press directly on the ruler. It can be used with dry or steam irons. The unique non-slip surface holds fabric in place for precise results. It is the latest addition to the Press Perfect line by Joan Hawley. Notes from Joan "Perfect size ruler for large tasks at the pressing station" and "Keep this handy ruler by the iron to measure , mark, and press".