Create pieces by tracing or Auto-Detect

What you are trying to accomplish

Turn the intended boundary in your source photo into a clean, closed, editable pattern piece. PatternForge offers two routes inside Create Pieces:

• Trace Manually — the dependable default.
• Auto-Detect Pieces — a Beta suggestion that you must review.

You can use both methods in one project.

Why it matters

The digital outline becomes the foundation for scale, seam allowance, fold behavior, markings, print layout, and export. PatternForge can record the boundary you choose, but it cannot decide which nested size line or construction line the designer intended.

Auto-Detect is not proof. Shadows, tissue, tape, printed text, nearby pieces, nested sizes, and the edge of the photo can all be mistaken for a pattern boundary. A manually traced outline can also be wrong if you follow the wrong line or copy every wrinkle in the paper.

Set and check true size before creating production pieces. If you deliberately continue unscaled, PatternForge keeps the result as an unchecked draft that may print at the wrong size.

Step by step

Trace Manually

1. Confirm the correct source image is visible and its true size has passed an independent check.
2. Identify the exact size line you want. Decide whether it is a Sewing line or Cutting line before you begin.
3. Open Create Pieces and choose Trace Manually.
4. Click or tap meaningful corners and changes in direction around the boundary. Use straight points for intentional straight edges and smooth points for curves. While tracing, X switches between straight and curved points on a keyboard.
5. Use as few points as you can while preserving the intended shape. Do not trace paper damage, fuzzy edges, or tiny camera noise.
6. Close the outline by returning to the first point, or finish a shape of at least three points with Enter, a double-click, or the visible close control on touch devices.
7. If PatternForge warns that the closing edge jumps across the piece, choose whether to keep tracing or deliberately keep that shape. Do not dismiss the warning without looking at the proposed closing line.
8. PatternForge opens the shared review flow. Use Adjust Shape to move points, insert a point where the shape truly changes, or switch a segment between straight and curved.
9. Open Shape check if it is not already shown. Use Zoom to problem for every Path Health concern, then decide from the source whether it needs a repair.

Auto-Detect Pieces (Beta)

1. Use a clear, high-contrast photo with one opaque piece separated from clutter when possible.
2. Open Create Pieces, choose Auto-Detect Pieces, and set true size first if prompted.
3. Choose Find pieces. PatternForge may honestly decline if the image is too difficult; manual tracing remains available.
4. Review every dashed candidate on the photo. Possible pattern piece means “inspect this starting point,” not “this edge is safe.”
5. Choose Keep only for a candidate that follows the intended boundary. Choose Fix edge to keep the suggestion and enter point editing immediately. Choose Skip for text, shadows, neighboring pieces, cropped shapes, or the wrong size line.
6. After accepting, perform the same full outline and Path Health review used for a manual trace.
7. Compare the piece to the source at close zoom and normal zoom. Then hide the source temporarily and judge whether the geometry still looks intentional.

What success looks like

• The intended size and boundary were chosen consciously.
• The outline is closed, does not cross itself, and contains no accidental spikes or loops.
• Straight edges remain straight, real corners remain corners, and curves flow without tracing every wobble.
• Path Health concerns have been inspected rather than accepted blindly.
• The piece aligns with the independently checked source at more than one zoom level.
• The piece has moved on to a meaningful name and its essential markings.

Common problems and recovery

Auto-Detect finds nothing

This is an honest Beta decline, not a dead end. Improve contrast and lighting if you can, isolate the piece, or choose Trace Manually.

A candidate touches the photo border

Treat the May be cropped warning seriously. Retake or recrop the image so the full piece is visible, or trace only after confirming the missing boundary from the physical source.

The candidate follows a shadow, ruler, text, or neighboring piece

Choose Skip. Do not spend time forcing an unrelated candidate to become the right piece when manual tracing will be clearer.

The outline looks lumpy

Remove unnecessary points before adding more. Smooth transitions at normal viewing size, then inspect at high zoom. The disturbance may begin one segment earlier than the visible bump.

The piece has a tiny gap

Use Adjust Shape and bring the two endpoints together, or use the outline close control in the Shape panel. A complete piece needs a sealed boundary.

The outline crosses itself

Use Shape check and Zoom to problem, then move or remove the points that create the crossing. Do not add seam allowance until the base outline is valid.

You traced the wrong nested size

Undo if the mistake is recent. Otherwise delete the incorrect piece and trace again from the correct line. Resizing a wrong size uniformly is not apparel grading and will not recreate the intended size.

You created pieces before checking true size

Use the calibration recovery choice carefully. Rescale the existing geometry only when it belongs to that exact photo and calibration change; otherwise retrace. A piece marked as scale unchecked should not be treated as print-ready.

Quick safety check

Ask these questions before adding details:

• Can I name the exact line and size I followed?
• Is the boundary closed and free of crossings?
• Did I inspect every Auto-Detect suggestion rather than treat it as proof?
• Does a second known measurement still agree with true size?
• Does the outline look clean with the photo hidden?

Related tools and next step

Continue with naming and labeling pieces. Use Select, Pan, Measure, and Advanced tools for inspection, and add seam allowance only after choosing whether the outline is a sewing line or cutting line.