Width Brush Tool

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Width Brush is an Astute Graphics tool for Adobe Illustrator that allows you to edit variable width stroked paths by simply brushing them. It supports adjustment by fixed amounts or by percentage, and includes pressure support for tablet input devices. Width Brush is part of the WidthScribe plugin.

Width Brush in Action

Width Brush in Action

Tool Location and Cursor Appearance

The Width Brush tool appears in Illustrator’s main toolbar (which must be in Advanced mode: View > Toolbars > Advanced).

Width Brush Tool Location

Width Brush Tool Location

The Width Brush tool’s cursor is a crosshair surrounded by a gray circle which indicates the brush diameter. Small badges distinguish between fixed value and percentage modes. A caption will appear if no paths are selected: 

Width Brush Cursors

Width Brush Cursors

Width Brush Tool Operation

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After the Width Brush tool is selected, its size can be changed either in its preferences dialog (see Width Brush: Preferences) or by pressing the keys assigned to Decrease Diameter and Increase Diameter in the native Keyboard Shortcuts dialog (the left and right square bracket keys respectively, by default, for English language keyboards). Its hardness, ranging from 0% to 100%, can only be changed in the preferences dialog.

When at least one path with a variable width stroke (or stroke that can be converted to a variable width stroke) is selected, clicking on it with the brush or dragging the brush across it will widen or narrow the stroke(s). Annotations will dynamically update while the mouse button is down to show the current stroke width:

Width Brush Basic Example

Width Brush Basic Example

The brush only makes one adjustment per drag; i.e. it does not flow continuously like a Photoshop airbrush. For example, if the adjustment were set to add the fixed amount of 3 pt of width to a stroke, then moving the cursor back and forth over a path will only add 3 pt at most, regardless of how many times the cursor passes over it. However, releasing the mouse button and making a new drag could add up to another 3 pt, and so on.

Width Brush Second Drag

Width Brush Second Drag

Brush hardness affects the smoothness of the transition between the original stroke width and the adjusted stroke width, as only positions towards the center of the brush get maximum adjustment:

Width Brush Hardness Comparison

Width Brush Hardness Comparison

Before pressing the mouse button down to click or drag, there are two keypresses which can be used:

  • Shift: All adjustments will be in the reverse direction. In other words, if the brush were set to add 1.7 mm to all stroke widths, then instead it would subtract 1.7 mm. If it were set to double stroke widths (e.g. make them 200% of their original width), then stroke widths would be instead halved (e.g. make them 50% of their original width).

  • Option/Alt: Makes the tool act exactly like the Width Eraser tool, which visualizes the width markers on the path(s) and removes those that the tool is passed over (except those at the start and end of the path). Its diameter is taken from that last used in the actual Width Eraser tool, and cannot be changed.

While dragging with the tool, the X key can be pressed to toggle its annotations on and off. This allows you to see the original width of the stroke(s). Annotations are drawn in the same color as that used for the Width Gradient tool.

Width Brush Preferences

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Doubleclicking the Width Brush tool in the toolbox (or pressing the Enter key when the tool is selected) will bring up its preferences dialog:

Width Brush Preferences Dialog

Width Brush Preferences Dialog

1. Size

The diameter of the brush, from 1 pt to 2500 pt. The value may also be changed using the keys assigned to Decrease Diameter and Increase Diameter in the native Keyboard Shortcuts dialog (the left and right square brackets keys respectively, by default, for English language keyboards).

2. Hardness

Similar to the hardness of a Photoshop brush; softer brushes will only adjust the stroke width fully at the center of the brush, thereby leaving a more gentle transition between the original stroke width and the adjusted stroke width. 

3. Adjust Widths by Fixed Amount

When enabled, stroke widths are adjusted by adding or subtracting the specified value from them.

4. Fixed Amount

The amount by which to adjust a stroke width, from –144 pt to 144 pt. Depending on the hardness of the brush, full adjustment may only occur at locations over which the center of the brush is passed.

5. Fixed Amount Input

Allows the fixed amount adjustment to be controlled by a stylus input device. For use with a mouse, the popup should be set to Fixed. Otherwise it may be set to any of the standard stylus inputs: Pressure, Wheel, Tilt, Bearing, or Rotation. If, for example, the input is set to Pressure, then only when the stylus is pushed down with maximum pressure will the adjustment amount reach the specified value.

6. Adjust Widths by Percentage

When enabled, stroke widths are adjusted by multiplying them by the specified percentage.

7. Percentage Amount

The percentage by which to adjust a stroke width, from 0% to 1000%. Depending on the hardness of the brush, full adjustment may only occur at locations over which the center of the brush is passed.

8. Percentage Input

Allows the percentage adjustment to be controlled by a stylus input device. For use with a mouse, the popup should be set to Fixed. Otherwise it may be set to any of the standard stylus inputs: Pressure, Wheel, Tilt, Bearing, or Rotation. If, for example, the input is set to Pressure, then only when the stylus is pushed down with maximum pressure will the adjustment amount reach the specified value.

9. Edit Stroke Type Selection

For paths with multiple strokes, chooses between editing all of its strokes and editing only the stroke that has focus.

Width Brush Edit Strokes Comparison

Width Brush Edit Strokes Comparison

10. Optimization

Reduces the number of width markers on the resulting path(s) after the brush has been applied. The optimization value can be set from 0 (no optimization) to 10, with a default of 3. Higher optimization values will remove more width markers, making the path profile smoother and easier to edit manually, but may result in slightly less accurate results compared to the unoptimized results.

11. Help Button

Opens the help documentation in the Astute Manager. If this does not automatically appear, please ensure your Astute Manager is running first.