When selecting grayscale printing in the printer driver, does this use only the black ink or all the ink cartridges to produce the grayscale image?
It depends on the following conditions:
Paper Type Setting
Machine Operation Mode
B/W PC Printing Mode
Plain Paper
Black
Inkjet Paper
Cyan + Magenta + Yellow + Black
Brother BP71 Photo Paper/
Brother BP61 Photo Paper/
Other Photo Paper
Cyan + Magenta + Yellow
Transparencies
Cyan + Magenta + Yellow
Slow Drying Paper
Cyan + Magenta + Yellow + Black
B/W Copy Mode
Plain Paper
Black
Inkjet Paper
Black
Brother BP71 Photo Paper/
Brother BP61 Photo Paper/
Other Photo Paper
Cyan + Magenta + Yellow
Transparencies
Cyan + Magenta + Yellow
B/W Fax Reception Mode
Plain Paper
Black
Inkjet Paper
Black
Brother BP71 Photo Paper/
Brother BP61 Photo Paper/
Other Photo Paper
Cyan + Magenta + Yellow
The machine uses color ink to clean the ink jet nozzles.
Refer to the Related FAQ at the end of the page for detail of "Cleaning" and "Grayscale Printing".