PURPOSE: To facilitate product development through the variation of merchandise with various expressions and displaying by forming charactristic patterns with combination of colors on the surface of metallic material used as building material for interior decoration and other purposes.

CONSTITUTION: A prodessed product of metallic material is prepared through the following steps: the surface of aluminum 1 is polished and blasted after masking with a rapped flower pattern on the surface to form the flower pattern. After the mask being removed, a color film 3 is formed on the surface of the aluminum 1 by the secondary electrolytic pigmentation coating method for optional coloring. The colored surface of the aluminum 1 is polished with a feather cloth for glossing.