The power of sfumato, the blending of colours or tones so that there is no perceptible transition, was used by Da Vinci and Gerhard Richter to represent an idea of female beauty and the expanse of a seascape, respectively.

Leonardo Da Vinci, Ginevra de’ Benci, c. 1475

Gerhart Richter, Seascape with Bird-1970

The power of outlining was used for a variety of seemingly conflicting presentations of subtlety/lightness by Botticelli, surrealism/playfulness by de Chirico and abstractness/stark purpose by Braque.

Sandro Botticelli, Primavera, c.1482

Giorgio de Chirico, Hector and Andromache, 1917

Georges Braque, Houses at L’Estaque, 1908

Can you help me to understand these technique or their purpose better?