Which Way Is This Form Leaning? 🌀

A few lines and the direction and volume become obvious.

Author

brooks kim
August 25, 2026

Hello, Artists!

Today I’m covering cross-contour lines — the topic I promised in the last cat drawing newsletter.

photo of a hand — hard to read the direction at a glance

Can you tell right away which way this form is leaning? It’s ambiguous. But there’s an easy way to read it: just draw a few grid lines across the surface.

Flow Lines and Node Lines

flow lines only on the left, node lines only on the right — the difference between the two

Cross-contour lines are made of two kinds of lines.

(A quick note: “flow line” and “node line” aren’t standard art terms — there isn’t really an established word for this distinction in English, so these are just what I call them.)

Flow lines — lines that run along the axis through the form, showing its overall curve and direction.

Node lines — lines that wrap around the flow lines to express volume.

Draw both together on long forms like arms, legs, or a tail, and the direction and volume become much clearer.

The Drawing Order

four stages building up in order — axis → key flow line → filling in flow lines → node lines

  1. Set the axis running through the form

  2. Draw one key flow line along the most protruding point, then a second key flow line crossing it at 90 degrees around the axis

  3. Fill in the flow lines between them

  4. Draw a key node line at the point where the form protrudes most, then add more node lines wherever the volume changes sharply

Don’t space these lines evenly — the key is finding where the form bends the most (the inflection points) and drawing there.

the full grid on the left, only the key lines left in red on the right

This gets even clearer on more complex, twisting forms. You can draw the full grid like the one on the left, but what actually defines the form are the key flow line and key node line left in red on the right. Everything else gets added around those key lines as needed.

The Payoff

a hand mapped with cross-contour lines on the left, the finished rendering built from that understanding on the right

Once you understand the form this way, the result is far more three-dimensional. The more you understand the mass, the better the finished piece turns out.

Of course, you don’t need to go through this process for every drawing — getting too caught up in form can make a piece feel stiff and lose some of its line quality. But here’s the interesting part: even just mentally running through these lines, without drawing them, changes the way you see form.

If you have any questions, just hit reply — I’m always happy to answer!

P.S. This piece was drawn with my Sketch Brush Set. If you want the same texture and feel, check it out below.

Get My Sketch Brush Set: https://9brookskim.gumroad.com/l/qrzmk

From. Brookskim