What is the benefit of gradually moving the light colour toward the dark colour during blending?

Correct answer: Middle tones form and the transition becomes smooth

Gradual blending follows the value-transition principle: small amounts of the light and dark colours are worked toward each other, creating intermediate tones. These middle tones remove a harsh boundary and make the change look smooth and continuous. The method does not change paper size or dry the brush, and careful control should prevent colour from crossing the intended boundary.