Patent ID: 8542400

Claim:
A printing system comprising: a printing unit that is configured to print a primary image and a watermark on a recording medium and that is capable of switching between a multicolor printing mode and a monochrome printing mode, one of the multicolor printing mode and the monochrome printing mode being set for the primary image; a storing unit that stores a plurality of watermarks and a plurality of group information each being an identifier for sorting the plurality of watermarks into groups; a watermark selecting unit that accepts a user's input selecting a watermark from the plurality of watermarks; at least one processor; and memory storing computer-readable instructions that, when executed by the at least one processor, cause the printing system to provide: a determining unit that determines, based on the watermark selected by the watermark selecting unit and the group information corresponding to the watermark, whether the watermark has an attribute indicating the monochrome printing mode; and a color restricting unit that, even if the multicolor printing mode is set for the primary image, controls the printing unit to print the primary image and the watermark in the monochrome printing mode if the determining unit determines that the watermark has the attribute indicating the monochrome printing mode.