Fill Tool

The Fill tool (also known as the paint bucket) lets you quickly fill enclosed areas with a character or color. It's essential for coloring large regions, replacing characters, and creating solid backgrounds.

Tip

Quick access: Press F to activate the Fill tool from anywhere in the application.

Basic Usage

Select the Fill Tool

Click the paint bucket icon in the toolbar or press F.

Choose Your Fill

Select the character and/or color you want to fill with.

Click to Fill

Click inside any enclosed area to fill it. The fill will spread to all connected cells that match the original content.

Fill tool filling an enclosed areaClick inside an enclosed shape to fill the entire area

Fill Modes

Character Fill replaces all matching characters with your selected character.

  • Original spaces become your fill character
  • Preserves existing colors
  • Great for adding texture to empty areas
text
Before:          After (fill with ░):
┌────────┐       ┌────────┐
│        │  →    │░░░░░░░░│
│        │       │░░░░░░░░│
└────────┘       └────────┘

Fill Options

Tolerance

Tolerance controls how similar cells must be to be included in the fill:

ToleranceBehavior
0Exact match only
1-25Slight variations included
26-50Moderate variations
51-100Wide range of similar content
Info

Higher tolerance is useful when filling areas with slight color variations or anti-aliased edges.

Contiguous vs Global

Contiguous (default) fills only connected cells that touch each other.

text
┌───┐   ┌───┐
│ A │   │ A │     Click here fills
└───┘   └───┘     only this region
  ↑
Click

Anti-leak Protection

Prevent fills from leaking through diagonal gaps:

text
Without anti-leak:     With anti-leak:
    ╲    ╲                 ╲    ╲
     ████╲   Fills          ╲    ╲  Stays
    ████╲    through        ╲    ╲  contained

Enable Anti-leak in the tool options when working with diagonal boundaries.

Advanced Fill Techniques

Pattern Fill

Instead of a single character, fill with a repeating pattern:

Enable Pattern Mode

Toggle "Pattern Fill" in the tool options.

Define Your Pattern

Enter a pattern string or select from presets.

Apply the Fill

Click to fill the area with the repeating pattern.

Example patterns:

text
Checkerboard: ░▓░▓
Dots:         . . . .
Bricks:       ▀▄▀▄▀▄
Waves:        ∿∿∿∿
Various pattern fillsDifferent pattern fills create unique textures

Gradient Fill

Combine the Fill tool with gradients for smooth transitions:

  1. Select an area with the Selection tool
  2. Choose Fill tool with gradient mode
  3. Click and drag to define gradient direction

See Gradients for detailed gradient options.

Replace All

Quickly replace one character with another across the entire canvas:

Set Fill Mode to Global

Disable "Contiguous" in tool options.

Select Target Character

Hold Alt and click on the character you want to replace.

Choose Replacement

Select your new character in the character picker.

Click Any Instance

Click on any instance of the target character to replace all.

Fill Boundaries

Understanding what stops a fill is crucial:

Hard Boundaries

These always stop fill operations:

  • Any non-matching character
  • Canvas edges
  • Selection boundaries (if active)

Soft Boundaries

These may or may not stop fills depending on settings:

  • Color differences (affected by tolerance)
  • Diagonal gaps (affected by anti-leak setting)
  • Transparent cells

Common Use Cases

Creating Backgrounds

text
Before:                  After:
  ★    ★    ★           ░░░★░░░░★░░░░★░░░
    ★      ★            ░░░░★░░░░░░░★░░░░
 ★     ★      ★    →    ░★░░░░░★░░░░░░░★░
    ★     ★             ░░░░★░░░░░★░░░░░░

Filling Shapes

After creating an outline with the Shapes tool:

text
┌────────────┐         ┌────────────┐
│            │    →    │████████████│
│            │         │████████████│
└────────────┘         └────────────┘

Recoloring Artwork

Change colors while preserving character structure:

  1. Set Fill to "Color Only" mode
  2. Select your new color
  3. Click on the area to recolor

Keyboard Shortcuts

ShortcutAction
FSelect Fill tool
Alt + ClickSample color/character from canvas
Cmd/Ctrl + ZUndo last fill