Exiting out of a Composition
Exiting out of a composition is just as important as entering. The exit has to have a logical direction as well as a visually pleasing path. If an element in the design causes the viewer to leave the painting abruptly, without seeing other relevant parts, the overall success of the piece is diminished. If you're dealing with a portrait that has nothing but a dark background, the viewer is forced to back out of the picture.
However, a portrait can have a more subtle way of exiting the picture. In the painting below, "Girl Reading a Letter at an Open Window" by Johannes Vermeer, the girl reading the letter is the dominant subject in the composition. Once our eye leaves the girl, it travels up the curtain on the right, circles to the red curtain near the top of the window frame, back to the letter, rotates around the girl's arm, head, and finally exits through the window.
Vermeer intentionally designed his composition so that the viewer will first find the most relevant subject, then follow an intended visual path (which circles the girl several times) before the eye leaves the design.
Painting above, by Michael Grimaldi, demonstrating the entrance and exit out of a composition. Notice how Grimaldi uses the greatest area of contrast, gazing direction, and pointing devices to intentionally lead the viewer on a distinct path throughout the picture.
In the drawing above, observe how Michael Grimaldi uses the dark values at the bottom of the picture as an entrance point while using the angles of the doorway and the antenna on the radio as pointing devices. These pointers lead the viewer to the girl standing on the right-hand side of the frame. Also, notice how the girl’s gazing direction reinforces an exit out of the design.