Descriptive lines: lines that help us understand what we are seeing.
Outlines: a line that surrounds a shape.
Contour lines: the outer edges of shapes.
Hatching: thin, closely spaced, parallel lines.
Crosshatching: hatching lines that cross.
Implied lines: lines that suggest an edge, rather than clearly define it.
Edge: where one shape or space ends and another begins.
Closure: our tendency to “see” completed figures where lines are left open.
Line of Sight: the lines along which people look.
Expressive line: lines that send us messages about what the artist wants his or her work to make us feel.
Line Personalities:
Line Shape or Movement: straight, curved, and jagged.
Line Direction: vertical, horizontal, and diagonal.
Abstract lines: are expressive and nonrepresentational; they are not used symbolize, outline, or look like shading.
Blind Contour Drawing: Definition (scroll down a bit)
Blind Contour Line Drawing Lesson Plan
Blind contour drawing context
Letter of Recommendation: Blind Contour Drawing