Line weight is how thick and dark a line is. Line quality is how the line behaves along its length: whether it swells and thins, stays smooth and sure, or breaks into many hairy little strokes. In the last unit you learned to make long, confident lines. Now you will learn where to make them heavy and where to keep them light.
Key idea
Use heavier lines for near edges, the shadow side, the edge in front where two forms overlap, and the bottom where an object sits. Use lighter lines for far edges, the lit side and small details.
Why it works
Varied weight copies what your eyes see. Edges on the shadow side look darker. Near things look sharper and stronger than far things. And where one form overlaps another, a heavier line on the front edge tells the eye which one is in front, even before you add any shading.
Worked example: Two apples
One apple sits in front of another and overlaps it. Which edge gets the heavier line: the front apple's edge where it crosses the back apple, or the back apple's edge?
- Where forms overlap, the edge in front should read first.
- A heavier line comes forward.
Answer: The front apple's edge.
Worked example: Far mountains
Leo draws a field with mountains far behind it. Should the mountains' outline be heavier or lighter than the fence in front?
- Far things look softer and paler than near things.
- A lighter line pushes the mountains back.
Answer: Lighter.
Common mistake
When every line has the same weight, a drawing looks flat, like a page in a coloring book. Before you finish, ask three questions: Where is the light? What is in front? What sits on the ground? Then go over those edges with heavier lines.