Acurit Rolling Ruler
No artist should be without this simply fantastic tool for drawing. It's a ruler, compass, protractor and T-square all in one. It is small and lightweight so it can be with you at all times. It has a 12" ruler graduated in 1/16" increments and is made of clear impact plastic. It has a calibrated roller for horizontal lines, protractor for angles and arcs, magnifier for inspection and calibrated guide holes that let you draw vertical lines. It is a blast to make squares, quadrants, grids, arcs, angles and circles with up to a 24" diameter and triangles. An artist toy if there ever was one. Makes cross-hatching and virtually any other drawing technique so much more fun! It even makes perspective drawing easier then ever before. If you're teaching drawing, add this to the supplies and you'll have students drawing more often and having more fun. Once you have one you'll never draw without one again.