Bristle Brushes: Shape & Bristles¶

Source¶

Brush Shape - Choose the shape of your custom brush. Click the shape thumbnail to open the image library of shapes. Individual bristles will be generated within the brush shape.

Texture Properties - Scale or change the brightness and contrast of the shape.

Rotate - Rotate the shape clockwise.

Flip Horizontally - Flip the shape horizontally.

Invert - Invert the shape.

Note

Shapes are accessible via the Help menu > Show Library folder, where you can paste any custom shape to their respective folder in PNG, JPG or BMP format.

Shape¶

Angle - Set the angle of the brush shape (0-360):

Rotation - Select the rotation mode of the brush shape:

None - The brush shape does not rotate.
Follow Trajectory - The brush follows the stroke's trajectory rotation.
Pen Tilt - The brush shape follows the pen tilt.
Pen Rotation - The brush shape follows pen rotation.

Tip

Brushes that follow a trajectory, pen tilt and pen rotation have a cursor displayed as a circle with direction. You can choose other cursor types in Preferences > Tools > Painting Cursor.

Note

You can select "Always use Pen Tilt / Rotation instead of Follow Trajectory in Brush Creator" option in Preferences > Tools. When selected, the brush shape follows the pen tilt or rotation if the pen supports them, even when "Follow Trajectory" is selected for brush rotation.

Force Rotation Mode - Lock the currently selected rotation setting for the particular brush so that no other settings override the rotation mode.

Bristles¶

Random Span - This setting controls the randomness in the placement of the bristles within the brush. (0-200) At 0, there is no randomness: bristles that add and remove impasto are evenly spaced and consistently positioned. Increasing the value introduces more randomness to their placement, resulting in a more natural and varied brushstroke.

Random Span at 0 (top), at 25 (middle) and at 100 (bottom)

Oscillation - Controls the subtle up-and-down movement of individual bristles while painting. (0-10 px) This adds natural variation to brushstrokes so they don’t look identical over time. At a value of 0, no oscillation is applied.

Oscillation at 0 (top), at 5 (middle) and at 10 (bottom)

Variation - Bristle brushes use two types of bristles: 'Add impasto' bristles - those that build up impasto peaks and 'Remove impasto' bristles - those that carve valleys in the impasto. Variation parameter (0-20) randomizes the sequence in which 'Add impasto' and 'Remove impasto' bristles are arranged within the brush. At 0, there is no randomness: the bristle order is fixed and predictable, e.g., peak–valley–peak from top to bottom. Increasing the value introduces randomness to this sequence, allowing for less uniform combinations, e.g., peak–peak–valley.

Variation at 0 (top), at 10 (middle) and at 20 (bottom)

Noise Frequency - Using Perlin noise, this setting controls the size of bristle groups that have similar behavior. (0-100) For example, bristles within a brush can behave differently in how they scratch the surface of the paper or how they react to mixing, blending or painting based on the pressure. At 0, brush will contain all bristles using the same values, while with higher values you can see several groups of bristles.

From the top: Noise Frequency at 0, at 10, at 50 and at 100 (bottom)

Random Noise - This setting controls the randomness of noise frequency. (0-100) At 0, there is no randomness. The higher the value the more noise used vs. smooth transitions from Perlin noise.

From the top: Random Noise at 0, at 5, at 50 and at 100 (bottom)

Per-bristle Pressure (Multiplier) - Set the pen pressure multiplier per bristle. (1-100) This parameter multiplies the Per-bristle Pressure parameter.

Per-bristle Pressure - Set the pen pressure per bristle. (1-100) - This slider controls how much variation is added to the pressure response of each bristle. At 0, all bristles follow the exact same pressure curve. As you increase the value, each bristle begins to respond differently to pressure.

Noise Frequency at 20. From the top, Per-bristle Pressure:Multiplier ratio: first 0:0, second 0:5, third 0:20, fourth 20:10, and fifth 20:20

Impasto Behavior - Adjusts the Pen Pressure curve for oil and acrylic impasto. With a linear curve, the thickness of the impasto will increase proportionally to the pressure applied with your tablet pen.

Impasto Behavior without a pen pressure curve (top) vs. with a pen pressure curve (bottom)

Note

Impasto Behavior curve is influenced by the 'Per-bristle Pressure' without its multiplier (Shape & Bristles > Bristles). This way, pen pressure for individual bristles may vary, resulting in impasto variations per each bristle.

Each bristle brush can consist of Thin bristles, Thick bristles and Edges.

Thin:

Activate thin bristles within the brush by checking the Enabled box.
Density - Set the density of the thin bristles within the brush. (1-100)

From the top: Density at 1, at 20, at 30, at 40 and at 50 (bottom)

Note

Density set to around 40-50 is usually sufficient for a brush preset. Higher Density values have a significant influence on performance.

Add Impasto - Add impasto to the thin bristles. The more impasto, the thicker the bristle. (0-100)

Add Impasto at 0 (top), at 20 (middle) and at 100 (bottom)

Remove Impasto - At 0 no bristles remove impasto. With higher values, the bristles start removing the impasto with the slider controlling the intensity of this effect. (0-100)

Remove Impasto at 0 (top), at 50 (middle) and at 100 (bottom)

Wave Length - Each bristle can periodically change its size and amount of impasto. This parameter controls the length of these waves. (1-100)

Wave Length at 10 (top) vs. at 30 (bottom)

Jitter - Randomly modifies the length of each wave. At 0 there is no randomness, all waves will have the same length. (0-100)

Jitter at 0 (top) vs. at 50 (bottom) while Wave Length is at 30

Min Width - Controls the minimum size a bristle will have during the wave. (0-100)

Min Width at 0 (top) vs. at 30 (bottom) while Wave Length is at 30

Thick:

Activate thick bristles within the brush by checking the Enabled box.
Density - Set the density of the thick bristles within the brush. (1-100)

Add Impasto - Add impasto to the thick bristles. The more impasto, the thicker the bristle. (0-100)

Remove Impasto - At 0 no bristles remove impasto. With higher values, half of the bristles start removing the impasto with the slider controlling the intensity of this effect. (0-100)

Width - Set the width of the thick bristles in pixels. (1-100)

Width at 0 (top), at 3 (middle) and at 10 (bottom)

Width Behavior - Adjusts the Pen Pressure curve for width of the bristles. With a linear curve, the width of the bristles will increase proportionally to the pressure applied with your tablet pen.

Width Behavior without a Pen Pressure curve (top) vs. with a Pen Pressure curve (bottom)

Note

Width Behavior curve is influenced by the 'Per-bristle Pressure' without its multiplier (Shape & Bristles > Bristles). This way, pen pressure for individual bristles may vary, resulting in width variations per each bristle.

Width Jitter - Set how much the width of individual thick bristles varies randomly. At low values, the thick bristles maintain more uniform widths. As the value increases, the thick bristle widths vary more significantly. (0-100)

Width Jitter at 0 (top) vs. at 50 (bottom)

Quality - Set the quality of the bristles. The higher the value, the better the quality. (1-100)

Quality at 0 (left), at 50 (middle) and at 100 (right)

Note

Quality set to around 40-50 is usually sufficient for a brush preset. Higher Quality values have a significant influence on performance.

Wave Length - Each bristle can periodically change its size and amount of impasto. This parameter controls the length of these waves. (0-100)

Jitter - Randomly modifies the length of each wave. At 0 there is no randomness, all waves will have the same length. (0-100)

Min Width - Controls the minimum size a bristle will have during the wave. (0-100)

Edges:

Activate edges within the brush by checking the Enabled box.
Add Impasto - Add impasto to the edges. The more impasto is added, the thicker the edge becomes. (0-100)
Width - Set the width of the edges in pixels. (1-100)
Pressure Behavior - This curve can be used to fine tune how edges react to Pen Pressure. Low values will produce thin edges with low impasto. At high values, edges will be wider and have stronger impasto.
Tilt Behavior - This curve controls how edges react to Pen Tilt. With curve set to horizontal line, edges on both sides of the brush strokes will have the same strength (influenced by Pressure Curve). With a linear curve, the strength of edges depends on the Pen Tilt in relation to the stroke.
Quality - Set the quality of the edges. The higher the value, the better the quality. (1-100)
Wave Length - Each bristle can periodically change its size and amount of impasto. This parameter controls the length of these waves. (1-100)
Jitter - Randomly modifies the length of each wave. At 0 there is no randomness, all waves will have the same length. (0-100)
Min Width - Controls the minimum size a bristle will have during the wave. (0-100)

Video tutorial

Learn more about Bristle brushes' settings in this video: Rebelle 8 New Features: Brush Creator Additions.