Where the bucket lives, and what it actually does
The rail is grouped. The Paint Bucket sits in the paint slot together with Gradient, Mesh Gradient and Spray, and Gradient is the slot's default occupant. Click the small triangle on that slot to open the flyout and pick Paint Bucket, or press U. Your pick sticks: the slot remembers whichever member you chose and keeps showing it.
Now the part people get wrong. The bucket does not recolour the shape you clicked. It snapshots the rendered canvas, flood-fills outward from your click point until it meets a colour boundary, traces that mask into polygons (an outer ring plus any holes, filled even-odd) and builds a new path from the result. You end up with a fresh object in your document. The artwork you poured between is left alone.
Because the trace starts from rendered pixels, the poured path follows what was on the screen rather than the exact bezier maths of the shapes around it. Expect a close approximation, not a perfect seam.
Pouring a region
- Pick the tool Press U, or open the paint slot's flyout and choose Paint Bucket.
- Set the colour you are about to pour Press , to open the colour picker. X toggles which paint is active, Shift+X swaps fill and stroke, D resets to the default white fill with a black stroke, and . switches the active paint to a gradient.
- Click inside the region Click once in the enclosed area. The pour happens on release and lands as a new path in the document.
- Judge the edges, then adjust If the fill escaped the region, the boundary has a gap. If it stopped short or spilled into a neighbouring tone, the threshold is wrong. Undo with Ctrl+Z, change the option bar, pour again.
The option bar
Pick the Paint Bucket and the context bar gives you five controls:
- Fill by: Visible colors, Red, Green, Blue or Lightness. This chooses which channel the flood compares against when it decides where the region ends.
- Threshold: 0 to 100, default 5. How different a neighbouring pixel may be before the flood treats it as a wall. Raise it to pour across soft or anti-aliased edges, lower it to respect close tones.
- Grow/shrink by: -20 to 20, default 0. Expands or contracts the traced outline afterwards. A small positive value tucks the new path under the surrounding strokes so no hairline shows.
- Close gaps: None, Small, Medium or Large, default Small. This is the leak fix.
- Reset to defaults.
Close gaps is the setting worth understanding. Hand-drawn outlines rarely meet exactly, and a two-pixel opening is enough for the flood to escape and fill your whole page. Step the setting up until the pour is contained. Start at Small, which is already on.
Live Paint is a different animal
Live Paint has its own rail button, not a group slot, and no keyboard shortcut. It does not flood pixels at all. It runs your overlapping paths through the same planar-region engine that powers Shape Builder, works out the true vector regions those crossings create, and fills the exact region you click with the current fill.
That difference matters. There is no threshold to tune and no gap to leak through, because the region is derived from geometry rather than from colour. The originals stay intact and the new fill piece is added on top.
So: reach for Live Paint when the region is bounded by real vector paths that cross each other, which is most line art and most diagrams. Reach for the Paint Bucket when the boundary is something the geometry does not describe, such as a placed image or a rendered result you want to trace by eye.
Keys worth knowing here
| Keys | Does |
|---|---|
| U | Paint Bucket |
| G | Gradient (the paint slot's default) |
| , | Open the colour picker |
| X | Toggle the active paint between fill and stroke |
| Shift+X | Swap fill and stroke |
| D | Default paint: white fill, black stroke |
| / | Set the active paint to none |
| . | Set the active paint to a gradient |
| Ctrl+Z | Undo the pour |
Live Paint has no shortcut. Neither does the Connector or the Blob Brush. Some comments in the source claim otherwise and they are stale.
Common questions
Why did my pour fill the entire page?
The region was not closed. The flood found a gap in the outline and escaped through it. Undo, raise Close gaps from Small to Medium or Large, and pour again. If it still escapes, the opening is genuinely large and you should close the path itself or use Live Paint, which cannot leak.
The bucket made a new shape instead of colouring my rectangle. Is that a bug?
No, that is the design. The Paint Bucket always traces the flooded area and creates a new path from it. To change an existing object's colour, select it with the Select tool (V) and set the fill in the colour picker instead.
When should I use Live Paint rather than the bucket?
Whenever the region you want is formed by vector paths crossing each other. Live Paint uses the real geometry, so there is no threshold to guess at and no gap to plug. The bucket earns its place on artwork the geometry does not describe, such as a placed bitmap.
Can I pour a gradient?
Press . to set the active paint to a gradient before you pour. For editing a gradient directly on an object, the Gradient tool (G) is the better route: drag on the object, then drag the on-canvas handles.