Of all the different wood joints you will make, one of the most difficult is one of the simplest – the miter joint. Let’s say you are making a frame and your layout tool is off by 0.08 mm (0.003”), This little 0.08 mm (0.003”) error multiplied by the eight cuts means that fourth corner now features an ugly 0.6 mm (0.024”) gap which is just under 1/32” of an inch, directly influencing the tightness of the joint and the appearance. Therefore, you need a precision miter square for highly accurate woodworking design, machine setup and block checking.