PURPOSE: To present high-quality and good-looking appearance to a product as in a spin pattern by printing many fine lines on the front of a transparent resin board in transparent ink using a silk screen printing technique, and printing many same lines on the back at a different angle from that of the lines on the front by the same printing technique.

CONSTITUTION: An ink line 11 is formed on the front of a resin board 8, and an ink line 11A is also formed on the back, and the ink line 11A is tilted at an angle (α) with the ink line 11. An incident beam is reflected in a complicated way on the surfaces of the upper and lower ink lines 11, 11A to form a special pattern. If the angle α is about 12°, a transparent line 13 and a white line 14 are arranged alternately and these become opaque as a whole. If the angle αbecomes further larger, the interval between the transparent line 13 and the white line 14 becomes close. If the angle α becomes small to 5W6°, a broad stripe pattern appears to make a transparent rhomboid part and a white color appear as if opaque rhomboids were arranged horizontally arranged alternately. If the angle α becomes further smaller to 2W3°, the wide transparent rhomboid and the wide white rhomboid appear as if they were horizontally arranged alternately.