Achieve accurate proportions every time with the Derwent Scale Divider. This invaluable drawing tool makes it easy to transfer measurements from real-life, photographs, and sketches to your canvas or paper. Use the tool to scale your pictures in ratios from 4:1 to 1:4. It's also helpful for getting the correct perspectives in drawings. Practical and portable, the Derwent Scale Divider folds neatly away when not in use and slips easily into your backpack or bag.