Abstract: Test printing apparatus for test printing, wherein printing ink is printed on a test substrate. An ultraviolet irradiation assembly is mounted adjacent the rotary path of the bearing surface bearing the test substrate, for emitting ultraviolet radiation against the test substrate. The apparatus has a control arranged for controlling the drive for imparting to the bearing surface a speed in the sense of rotation, which during the irradiation of the test substrate by the irradiation assembly is different from the speed that is imparted by the drive to the bearing surface during the printing of the test substrate. An irradiation assembly and a method for test printing are also described.