| Tool | How selection affects it |
|---|---|
| Brush | Brush strokes are clipped to the selection boundary. You can paint freely — only selected cells change. |
| Fill | Flood fill is constrained to the selection. The fill expands only within selected cells. Connected cells outside the selection are ignored. |
| Shape | Rectangles and ellipses are clipped to the selection. Cells inside the shape but outside the selection stay empty. |
| Text | Stamped text is clipped to the selection. Characters that fall outside the selected area are not rendered. |
| Line | Line segments are clipped to the selection. Only the portions of the line within the selection appear. |
| Confetti Cleanup | Auto mode cleans only selected cells. Brush mode operates only within the selection. |
Selection & Tools
How Brush, Fill, Shape, Text, Line, and Confetti Cleanup tools interact with the active selection. Edit only within the selected region.
Location: General behavior
Keyboard & modifiers
- V
- Switch to Selection tool
- Cmd+A Ctrl+A
- Select all
- Cmd+D Ctrl+D
- Deselect
Basics
When you have an active selection, every drawing tool automatically restricts its edits to the selected region. Cells outside the selection boundary are protected — you can't accidentally paint, fill, or stamp over them.
This is one of the most powerful features in the editor. It lets you work on a specific area without worrying about messing up the rest of the pattern.
How it works
Behind the scenes, the selection is a binary mask — a grid the same size as your pattern where each cell is either "selected" (editable) or "not selected" (protected).
When you use a drawing tool:
- The tool calculates which cells it would normally affect (brush stroke, fill region, shape area, etc.).
- Those cells are filtered through the selection mask.
- Only cells that are both affected by the tool AND inside the selection are actually modified.
This happens automatically. You don't need to enable or configure anything — if a selection exists, it's active.
To remove the constraint, press Cmd/Ctrl+D to deselect.
Tool-by-tool behavior
Visual feedback
When a selection is active, the unselected area is dimmed with a semi-transparent overlay (marching ants border marks the selection edge). This gives you a clear visual of where you can and can't edit.
The selection boundary stays visible even after switching tools. You'll always know which region is selected and protected.
Tips & gotchas
- Selection persists across tools. Draw a selection once, then switch between Brush, Fill, Shape, and Text freely. The selection stays active until you explicitly deselect.
- Cmd/Ctrl+D to remove. When you're done editing a specific area, deselect to go back to full-canvas editing.
- F to fill selection. With the Selection tool active, press F to fill the entire selected area with the active color. No need to switch to the Fill tool for this.
- Selection + Fill is powerful. Select an irregular shape with the Lasso or Magic Wand, then switch to Fill to color specific regions within it.
- Confetti Cleanup respects selection. Run Auto cleanup on just the selected area — useful for cleaning up one section without affecting areas you've already hand-edited.
- Symmetry works with selection. If you're using Brush symmetry within a selection, the mirrored strokes are also clipped to the selection.
- No partial cells. A cell is either inside or outside the selection — there's no partial selection. The mask is binary.