They say: “measure twice — cut once”, but if one of the shear blades to cause a spark or graviroval marker centimeter scale, as shown in the figure, from a preliminary marking in many cases will be abandoned. It is sufficient initially to dissolve the scissors so that the point of intersection of the blades were “0” and then to control the magnitude of the slit displacement of this point relative to the scale.
A. VASILIEV, Krasnoyarsk