Canon PIXMA MG3660 Online Manual page 320

Grayscale Printing
Set grayscale printing. Grayscale printing refers to the function of converting your document to
grayscale data in the printer to print it in monochrome.
When you check the check box, both monochrome and color documents will be printed in monochrome.
When printing a color document, be sure to uncheck the check box.
Related Topics
Setting the Print Quality Level (Custom)
Printing a Color Document in Monochrome
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