1, The surface of the imprinting rubber roller is not delicate enough or there are foreign objects such as dust, which cause the ink here is not thick enough. 2, The plasticizers and lubricants contained in the film float to the surface, which hinders the normal transfer and lubrication of the ink. 3, Ink viscosity is too high, drying too fast or lack of adhesive, resulting in ink transfer, poor wetting. 4, The printing pressure is too small or the printing plate itself is defective.