The purpose of test cut is to adjust the oscillating current and amplitude so that the shadow, mid-tone, and highlight values produced by the engraving meet the technical requirements. Different dot shapes are achieved by varying the rotation speed, feed rate, and engraving frequency during the electro-engraving process. Test cut is a highly critical task, as it directly affects the tonal gradation of printed materials. Therefore, during test cut, corresponding shadow, mid-tone, and highlight dots should be selected based on different screen rulings and dot shapes. The width and height of the dots can be determined using a dot testing instrument.

Test cut significantly impacts the size of highlight and shadow dots. The larger the test engraving value, the larger and deeper the engraved cells become, resulting in greater ink storage capacity. For this reason, all plate-making factories treat test cut dots as a standardized procedure, establishing specific process parameters to ensure the standardization of test cut work.