Draw the Young-Woman/Old-Woman Illusion: Shared Contours and Dual Readings

Object Drawing Lessons

This lesson teaches a specific drawing skill: constructing an ambiguous figure in which the same set of lines supports two different face interpretations. The classic young-woman/old-woman illusion works because a single contour can serve as a jaw in one reading and a nose in the other, while an ear becomes an eye and a necklace becomes a mouth. You will learn a convention for labeling shared contours, build the figure from a simple geometric scaffold, and test whether your drawing flips between readings. The goal is not portrait realism but controlled ambiguity: every line must do double duty without collapsing into a single obvious face.

Practice materials: Printable downloads are not available for this lesson yet. Use the instructions and four exercises below.

The dual-reading convention

Adopt a labeling convention before drawing. Use two colored pencils or two line styles: a solid line for contours shared by both readings, and a dashed line for features that belong to only one reading. Label each shared contour with both roles, for example 'jaw / nose bridge' or 'ear / eye'. This convention makes the ambiguity explicit and checkable. Because letter styles and face shapes vary, there is no single correct drawing; any contour set that reliably produces both readings under the convention is valid.

The figure is built around a vertical axis. The young woman's face is turned slightly right; the old woman's face is turned slightly left and tilted down. The shared right contour runs from crown to chin. Its lower segment forms the young woman's jaw and chin and, in the old-woman reading, the old woman's nose tip; the adjacent cheek line serves as the old woman's nose bridge. A second shared contour on the left side at eye level forms the young woman's ear and the old woman's eye. The young woman's necklace becomes the old woman's mouth. Keep these three mappings fixed; everything else is adjustable.

1. Draw a light vertical axis and mark three horizontal levels: crown, eye line, chin.
2. Sketch the shared right contour as a single smooth curve from crown to chin; label it 'jaw / nose tip' and note that the adjacent cheek line serves as the nose bridge.
3. Place the ear/eye contour on the left side at eye level; label it 'ear / eye'.
4. Add the necklace/mouth curve below the chin level; label it 'necklace / mouth'.
5. Add only the minimum unique features for each reading, using dashed lines.
6. Check the flip: view the drawing from about one meter away and note which face appears first.

Building the shared contour

Start with a geometric scaffold rather than a finished face. Draw an oval for the young woman's head, then a second oval offset downward and to the right for the old woman's head, so the old woman's nose region can meet the young woman's right edge. The overlap region is where shared contours live. Trace the right edge of the young woman's oval; its lower segment becomes the old woman's nose tip, while the adjacent cheek line reads as the nose bridge. The curve must be smooth enough to read as a jaw and prominent enough to read as a nose. Adjust the curvature until both readings are plausible at normal viewing distance.

Use simple checkable arithmetic to keep proportions consistent. If the young woman's head oval is 10 units tall and 7 units wide, place the eye line at 5 units from the top and the chin at 10 units. The old woman's oval can be 9 units tall and 6 units wide, offset 2 units down and 1 unit right. These numbers are hypothetical examples; measure your own paper and adjust. Record your chosen units on the page so the drawing is reproducible.

1. Draw the young woman's head oval at your chosen scale and label its height and width.
2. Draw the old woman's head oval offset down and right; label the offset in the same units.
3. Trace the shared right contour and mark its two roles.
4. Erase construction lines that do not serve either reading.
5. Re-draw the shared contour with a solid line and unique features with dashed lines.

Feature shifts and the flip test

The illusion depends on feature shifts, not on adding detail. The young woman's ear is a small curved shape at eye level on the left side; in the old woman reading, that same curve becomes an eye. The young woman's necklace is a short curve below the chin; in the old woman reading, it becomes a mouth. The young woman's jaw and chin form the old woman's nose tip, while the adjacent cheek line serves as the old woman's nose bridge. Draw each shift with the labeling convention so a viewer can trace the mapping.

Test the flip by viewing the drawing from different distances and angles. A valid drawing flips within about five seconds of sustained viewing at one meter. If one reading dominates, adjust the shared contour's curvature or the placement of the ear/eye curve. Do not add shading or texture to force a reading; ambiguity comes from contour structure. Record which reading appears first and how long the flip takes; these are your check measurements.

1. Label the ear/eye curve with both roles and check its position at eye level.
2. Label the necklace/mouth curve and check it sits below the chin level.
3. View from one meter and time the flip; record the result.
4. If no flip occurs, adjust one shared contour by a small amount and retest.
5. Repeat until both readings appear within five seconds.

Valid alternatives and rubric

Because face shapes and letter styles vary, many valid solutions exist. A drawing may use a rounder jaw, a sharper nose, or a wider ear/eye curve, provided the dual mapping remains traceable. The rubric rewards explicit labeling, consistent units, a working flip test, and a clear distinction between shared and unique contours. It does not reward realism or a single 'correct' face. Any drawing that meets the rubric is acceptable, including ones that look quite different from the classic plate.

Keep your units consistent throughout. If you measure in centimeters, label all offsets in centimeters. If you use arbitrary units, state that they are hypothetical examples. Do not invent printer tolerances or hardware standards; measure your actual paper and pencil. The check method is simple arithmetic plus the flip test: count the shared contours, verify each has two labels, and time the flip at one meter.

1. Count shared contours and confirm each has exactly two role labels.
2. Measure the offset between head ovals in your chosen units and record it.
3. Run the flip test three times and record the times.
4. Compare your drawing to the rubric and note any missing labels.
5. Revise one contour at a time and retest.

Worked example

A student draws a young woman's head oval 10 units tall and 7 units wide, with the eye line at 5 units and the chin at 10 units. The old woman's oval is 9 units tall and 6 units wide, offset 2 units down and 1 unit right. The shared right contour is labeled 'jaw / nose tip' with the adjacent cheek line noted as the nose bridge, the ear/eye curve is at eye level on the left side and labeled 'ear / eye', and the necklace/mouth curve sits 1 unit below the chin and is labeled 'necklace / mouth'. The student views from one meter and the drawing flips in four seconds. Is this a valid solution?

Four practice exercises

Common mistakes

• Drawing a complete young woman first and then trying to add old-woman features on top. Build from the shared contour outward. Draw the scaffold and the three shared mappings before adding any unique feature.
• Using shading or texture to force one reading. Remove shading and rely on contour structure. Ambiguity should come from line roles, not tone.
• Labeling only one role per shared contour. Apply the convention: every shared contour gets both labels, for example 'jaw / nose tip' or 'ear / eye'.
• Mixing units when recording offsets. Choose one unit, state it on the page, and convert all measurements to that unit.

Self-check rubric

• Three shared contours are present and each has two role labels.
• Units are stated and used consistently for all measurements.
• Unique features are drawn with dashed lines and do not force a single reading.
• The flip test is recorded and completes within five seconds at one meter.
• The drawing is reproducible from the recorded measurements.

Questions and answers