A line is an identifiable path created by a point moving in space. It is one-dimensional and can vary in width, direction, and length. Lines often define the edges of a form. Lines can be horizontal, vertical, or diagonal, straight or curved, thick or thin. They lead your eye around the composition and can communicate information through their character and direction.
Horizontal lines suggest a feeling of rest or repose because objects parallel to the earth are at rest. In this landscape, horizontal lines also help give a sense of space. The lines delineate sections of the landscape, which recede into space. They also imply continuation of the landscape beyond the picture plane to the left and right.
Saint Bavo, Haarlem, Pieter Jansz. Saenredam, 1634
Vertical lines often communicate a sense of height because they are perpendicular to the earth, extending upwards toward the sky. In this church interior, vertical lines suggest spirituality, rising beyond human reach toward the heavens.
Cabinet, French, about 1785
Horizontal and vertical lines used in combination communicate stability and solidity. Rectilinear forms with 90-degree angles are structurally stable. This stability suggests permanence and reliability.
Diagonal lines convey a feeling of movement. Objects in a diagonal position are unstable. Because they are neither vertical nor horizontal, they are either about to fall or are already in motion. The angles of the ship and the rocks on the shore convey a feeling of movement or speed in this stormy harbor scene.
A Storm on the Mediterranean Coast, Claude-Joseph Vernet, 1767
Pool, Saint-Cloud, Eugène Atget, 1915–1919
The curve of a line can convey energy. Soft, shallow curves recall the curves of the human body and often have a pleasing, sensual quality and a softening effect on the composition. The edge of the pool in this photograph gently leads the eye to the sculptures on the horizon.
From the J. Paul Getty Museum: https://www.getty.edu/education/teachers/building_lessons/formal_analysis.html
