Cross-contour drawing practice

Draw the Unseen

Every form has a back side you can't see. Wrap it in loops until you can.

Start PracticingTry one loop

Try it · one loop

Wrap the form

A cross-contour loop is the line a slice through the form would leave on its surface. Draw one around the middle of this cylinder, including the half that turns away from you. Then compare it with the real one.

Solid lines are the parts you can see. Dashed lines are hidden behind the form.

A tablet shows a glossy 3D torus while an artist draws it on paper with cross-contour loops
Fig. 01 — From screen to paper

For every level

Designed for artists of all levels

This tool helps you practice constructing 3D shapes by drawing cross contour lines within a set time limit.

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Fundamentals

Start Simple, Master Complex

Understanding and drawing complex shapes begins with mastering simple forms. By using this tool, you'll gain a deeper understanding of form from the inside, improving your ability to visualize and create 3D structures.

  1. 01 / Cube

    Loops on a box are its sections: straight on each face, turning at every edge.

  2. 02 / Sphere

    Every loop is an ellipse. They thin out as they approach the silhouette.

  3. 03 / Cylinder

    Keep each loop parallel to the end caps, not to the page.

  4. 04 / Cone

    Loops shrink toward the tip but keep the tilt of the base.

  5. 05 / Anything

    Then the same thinking on generated forms, against the clock.

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An artist sketching simple forms wrapped in cross-contour lines, with one torus traced in orange
Fig. 03 — A new form, every session

Generated forms

New Shapes for Every Practice!

Every time you practice, a new image of shapes is generated just for you from our exclusive 3D assets, ensuring a unique experience that allows you to explore and refine your artistic skills.

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Illustration of an elegant archer drawing her longbow, outlined in orange light

Construction

Enhance your construction skills

Regular practice with this tool will boost your construction skills, which are essential for both 2D and 3D art.

Move over the drawing to see what holds it up.

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