Which subtractive primary mixture produces red in printing?

Correct answer: Magenta and yellow

The governing concept is subtractive CMY mixing. Magenta ink absorbs much of the green component, while yellow ink absorbs much of the blue component. The light remaining to be reflected is mainly red, so magenta plus yellow produces red in an idealized printing model. Cyan plus yellow tends toward green, and cyan plus magenta tends toward blue; adding black would darken rather than define the basic mixture.