Expression settings

Corel Painter lets you control brush effects along the stroke based on a number of real-time input factors. For example, many brushes vary their opacity or size in response to changes in stylus pressure. These responses reflect their default settings. You can use the Expression settings to vary these effects in response to other factors, such as stroke direction or velocity.

Expression settings are linked to the following controls: Opacity, Grain, Size, Angle, Airbrush (Feature and Flow), Thick Paint, Impasto, Liquid Ink, Stroke Jitter, Blending (Saturation and Bleed), Color Expression, and Particles. In addition, for some of the brush controls that use Expression, you can adjust the Min setting to specify the range of variation that you want the expression to apply. The Min setting represents a percentage of the specific setting, such as Opacity, and it must be linked to an expression to have an effect. For example, if you choose the Pressure expression on the Opacity panel, set the Opacity slider to 50%, and then set the Min Opacity slider to 20%, the more stylus pressure you apply, the more opaque the brushstroke will be.

Direction adjusts the angle value of the direction controller. When the expression is set to Direction, it specifies the angle at which a brushstroke narrows or widens, which is particularly useful for calligraphic effects.

Some brush controls such as Size, Opacity, Angle, Stroke Jitter, Color Expression, and Color Variability can also be linked to audio input. For more information, see Audio Expression.

To choose an Expression setting

To	Do the following
Disable the expression setting	Choose None from the Expression list box.
Adjust the brushstroke based on the dragging speed	Choose Velocity from the Expression list box. Dragging quickly minimizes the setting; dragging slowly increases it.
Adjust the selected brushstroke based on the direction of the stroke	Choose Direction from the Expression list box, and move the Direction slider.
Adjust the brushstroke based on stylus pressure	Choose Pressure from the Expression list box. Greater pressure increases the setting for that brush feature.
Adjust the brushstroke based on the wheel setting on an airbrush stylus, specifically the Intuos Airbrush stylus	Choose Wheel from the Expression list box. The maximum value is set when the wheel is pushed all the way forward. The minimum is set when the wheel is pushed all the way back.
Adjust the brushstroke based on the angle of the stylus from the tablet	Choose Tilt from the Expression list box. For example, when the stylus is perpendicular to the tablet, Tilt is set at zero.
Adjust the brushstroke according to the direction in which the stylus points	Choose Bearing from the Expression list box.
Adjust the brushstroke as you turn a flat-tip Intuos Art Pen that supports 360-degrees of barrel rotation sensitivity	Choose Rotation from the Expression list box.
Adjust the brushstroke according to the luminance of the clone source	Choose Source from the Expression list box. Higher luminance (closer to white) increases the setting for that component, producing a wider stroke.
Adjust the brushstroke on a random basis	Choose Random from the Expression list box.
Reverse the effect of an Expression setting	Click the Invert button .

Not all stylus models convey tilt, rotation, or bearing information.