GIMP Free Select Tool: Combine Curves and Lines

The Free Select tool in GIMP allows you to combine freehand curves with straight polygonal segments within a single selection path without toggling a specific setting in the Tool Options panel. By alternating between single-clicking and dragging the mouse, GIMP dynamically switches between point-to-point polygon lines and freehand drawing, enabling precise and flexible selections around complex subjects.

How the Combined Mode Works

In GIMP, the Free Select tool operates in hybrid mode by default. Rather than relying on a checkbox or mode switch, the tool determines whether to draw straight lines or freehand curves based directly on your mouse or stylus input:

  • Polygonal Straight Lines: Click once to place an anchor point, release the mouse button, move your cursor to the next location, and click again. A straight segment connects the two points automatically.
  • Freehand Curves: Click and hold down the primary mouse button, then drag the cursor along the contours of your object. GIMP generates a smooth, curved path that follows your movement.

Step-by-Step Technique to Combine Both

  1. Activate the Tool: Select the Free Select tool from the Toolbox or press the keyboard shortcut F.
  2. Start a Straight Line: Left-click on your image to create your first anchor point. Move the cursor away and click again to create a straight line segment. Continue clicking point-to-point for straight edges.
  3. Transition to Freehand: From your last anchor point, press and hold the left mouse button, then immediately drag along the curved edge of your subject.
  4. Transition Back to Straight Lines: Release the mouse button. The end of your curve becomes the next anchor point. Move the cursor to a new location and single-click to resume straight segments.
  5. Close the Selection: Connect back to your starting point and click on it, press Enter, or double-click anywhere inside the path to finalize the active selection.

Relevant Tool Settings to Optimize Your Path

While the hybrid behavior itself is controlled through cursor actions, several core settings in the Tool Options dock affect how the combined selection renders:

  • Antialiasing: Keep this checked to smooth out the transition between straight edges and freehand curves, preventing pixelated steps along the border.
  • Feather Edges: Enable this setting and adjust the radius if you require a soft, blended transition rather than a hard boundary between the straight and curved segments.
  • Selection Modes (Replace, Add, Subtract, Intersect): Use these modes if you prefer to build the selection incrementally by combining separate polygon and freehand passes.