Magnetic whiteboard square stencil

A magnetic stencil for drawing squares on a whiteboard. It is very light but sturdy, so the angles are always right. Because it uses magnets to stick to the whiteboard surface, you do not have to hold the stencil with your hand while drawing the shape. Two stencils are included in the default print profile, with internal measurements of 10cm and 20cm. The walls are 1cm thick, so the external measurements are 12cm and 22cm respectively. The included OpenSCAD file allows you to specify custom sizes, as well as different widths, thicknesses and magnet sizes.