In art, an implied line is defined as a line that suggests the
edge of an object or a plane within an object. The line may be
broken by intermittent marks, it may be defined by value, color, or
texture, or it may not be visible at all. With any implied line,
our brain interprets that the line must exist, so this is a
powerful tool that any artist can use.
An implied line usually describes a subtle change of plane. For
example, in a portrait drawing, we often use implied line across
the bridge of the nose or along the jaw. A full line drawn for
either facial feature would suggest too sharp of an angle and
appear more like the line found along the edge of a box.
Implied lines give works of art a sense of motion and keep the
viewer engaged in a composition. We can see numerous implied lines
in Jacques-Louis David’s Oath of the Horatii, connecting the
figures and actions of the piece by leading the eye of the viewer
through the unfolding drama.
Implied line takes advantage of the human eye’s tendency to
fill in a line, even when what we see is not really a line.
Artists study great paintings and drawings, analyzing the
implied lines and other types of lines or the absence of lines to
discover the infinite ways to create the illusion of figures in
space, knowing that implied line is one of the handiest tools for
mimicking nature within the framework of a design.