The BeforeYouDraw system, explained.

What the system actually does

BeforeYouDraw analyzes an uploaded portrait photo and produces a structural plan. The plan is composed of layers, each generated by a specific algorithm:

• Four-value posterization
  The photo is reduced to four discrete tone bands using percentile-based thresholding. This eliminates photographic gradient and reveals tonal structure.
• Shadow shape extraction
  The shadow tier is isolated and rendered as connected silhouettes. Shadows are treated as shapes, not features.
• Midtone mapping
  The midtone tier is isolated separately so the artist can see form turning. On toned paper, this layer is hidden because the paper itself provides the midtone.
• Anchor proportion grid
  Reference lines drawn through facial landmarks: eye line, brow line, nose base, mouth line, chin line, centerline.
• Anchor points
  Five reference points: pupil-left, pupil-right, nose-base, mouth-center, chin. These lock the drawing’s proportion.
• Contour with form centerline
  The major contour edges plus the form centerline that traces the head’s vertical midline. The centerline curves with head rotation, making it the strongest indicator of the head’s pose in space.
• Lost-and-found edges
  Edges that should be soft, broken, or absent — rendered with dashed strokes. This teaches the artist to break the “outline everything” habit.
• Photo reference (optional)
  A faint grayscale version of the source photo, available as an optional layer for users who want to see how the layers map to the original.

The three Approaches

A single Approach setting controls which layers are emphasized and how literally each is rendered.

Approach	Anchors	Edges	Best for
Architectural	5 (with labels)	Hard, uniform	First attempts; learning to see
Studio	4	Mixed (lost-and-found)	Working artists with proportion fluency
Expressive	3	Soft, gestural	Confident artists; planning aid only

Paper-aware rendering

The plan’s appearance and the recommended media adapt to the paper. This isn’t cosmetic — it’s strategic. Toned paper requires a different value strategy and different media than white paper.

On white paper, the paper is your highlight. Build values down from there. Vine charcoal for blocking, willow for refining shadows, compressed for accents.

On mid-gray paper, the paper is your midtone. Don’t fill it in — let it show through. Use vine and compressed charcoal for darks, white charcoal for highlights. The drawing is built in two directions from the paper’s tone.

On warm tan paper, the paper provides midtone with a warm cast. Charcoal sits warm rather than cold. Sepia or willow for shadows, compressed for accents, white Conté for highlights.

The seven-step guided flow

After the plan is revealed, follow the seven-step drawing flow or work freely from the plan. The seven steps mirror the order in which an experienced portrait artist actually works:

1. Step 1 — Anchor placement.
   Place the proportion anchors on the paper before any other mark.
2. Step 2 — Find the four values.
   Block in tone tiers as flat shapes.
3. Step 3 — Block in shadow shapes.
   Draw shadows as connected silhouettes.
4. Step 4 — Detect edges.
   Mark hard, soft, or lost edges.
5. Step 5 — Refine contour.
   Draw the contour with variable weight.
6. Step 6 — Soften and refine.
   Blend midtones; lift highlights.
7. Step 7 — Add accents.
   Apply darkest darks last.

What BeforeYouDraw is not

BeforeYouDraw does not draw the final image. It does not generate AI artwork. It does not replace the user’s hand. The plan is a guide; the drawing belongs to the user.

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