Madonna and Child Enthroned with Saints, Raphael, c. 1505 (left)
Holy Family with St. Francis, Rubens, 1630s (right)
As Susan Woodford explains in her Looking at Pictures, these two images exemplify the distinction made by Wolfflin between the closed form-typical of Renaissance works such as that of Raphael-and the open form-typical of Baroque works such as that of Rubens.
In the closed form of the Renaissance picture [Raphael] all the figures are balanced within the frame of the picture. The composition is based on verticals and horizontals that echo the form of the frame and its delimiting function. The male saints at the sides close off the picture with strong vertical accents; these are repeated by the vertical accents formed by the bodies of the female saints, and finally, in the centre, by the throne itself. Horizontal accents are provided by the steps of the throne at the bottom, which emphasize the lower boundary of the frame, and the horizontal canopy above, which terminates the painting at the top. The picture is entirely self-contained. The closed form conveys an impression of stability and balance and there is a tendency towards a symmetrical arrangement (though, of course, it is not rigid-notice the alternation of profile and full face on the right and left pairs of male and female saints).
In the open form of the Baroque painting [Rubens] vigorous diagonals contrrast with the verticals and horizontals of the frame. Diagonal lines not only play on the surface of the picture, but also sweep back into the distance. Figures are not simply contained within the frame, but are cut off by it at the sides. There is a feeling of unlimited space that flows beyond the edges of the picture. The composition is dynamic rather than static; it suggests movement and is full of momentary effects, as opposed to the tranquil repose of the Renaissance painting. (Woodford, Looking at Pictures, 91-2).