Issue creating a new pattern piece when curves are involved

Daiane_Martins · December 31, 2025, 3:30am

Hi,

I’m having an issue in Seamly2D when creating a new pattern piece that depends on existing curves (see attached image).

While creating a new Pattern Piece works, the software seems to read curves only when points are in a strict sequence (e.g. A1, A2, A3…). When curves are built from non-sequential points, Seamly appears to read only points and straight segments, not the full curve geometry.

As a result:

curves lose continuity or change behavior
parts of the curve seem to remain linked to the original piece
the derived shape becomes inconsistent

Is this expected behavior? What is the recommended workflow for creating a new pattern piece based on curves?

Thanks.

Douglas · December 31, 2025, 4:06am

Since all points must be selected clockwise… this includes curves which are really just a vector of points. If a curve is going counterclockwise it needs to be reversed. Note: You can tell which direction a curve is going by the arrow:

Usually a curve will automatically reverse when selecting, but if not - holding the SHIFT key while selecting will reverse it. Note: Follow the tips in the status bar:

When possible you should always draft your curves going clockwise.

Also if there are any notch points included along the curve, you need to select the curve, select the notch point, then select the curve again.

If the curve needs to be reversed and you missed reversing it while creating a piece… you can always just reverse it in the Pattern Piece Tool path:

Note the curve, notch point, curve in the path here:

Also it’s best practice to always include the beginning and end points of a curve in the path when creating a piece. For one you can then control the corner angle in the Seam Allowance: