A dual brush combines two tips to create
brush marks. The second brush texture is applied within the brush
stroke of the primary brush; only the areas where both brushstrokes
intersect are painted. Set options for the primary tip in the Brush
Tip Shape section of the Brushes palette. Select a second brush
tip from the Dual Brush section of the Brushes palette, and set
any of the following options.

Brush strokes created with a single tip (left) and with dual
tips (right)
- Mode
-
Sets a blending mode to use when combining brush marks from
the primary tip and the dual tip. (See List of blending modes.)
- Diameter
-
Controls
the size of the dual tip. Enter a value in pixels, drag the slider, or
click Use Sample Size to use the original diameter of the brush
tip. (The Use Sample Size option is available only if the brush
tip shape was created by sampling pixels in an image.)
- Spacing
-
Controls
the distance between the dual tip brush marks in a stroke. To change
the spacing, type a number, or use the slider to enter a percentage
of the tip diameter.
- Scatter
-
Specifies how dual tip brush marks are distributed in a stroke.
When Both Axes is selected, dual tip brush marks are distributed
in a radial direction. When Both Axes is deselected, dual tip brush
marks are distributed perpendicular to the stroke path. To specify
the maximum percentage of scattering, type a number or use the slider
to enter a value.
- Count
-
Specifies the number of dual tip brush marks applied at each
spacing interval. Type a number, or use the slider to enter a value.