Paintbrush

The Paintbrush tool, combined with a Tip applies solid even strokes to the canvas. The main difference between the Paintbrush and the Airbrush tools is that the Paintbrush applies the paint with no internal blending, which is to say the paint comes out at full strength whereas the Airbrush layers on the paint daubs as you repeat strokes.
You can select the tool from the Paint interface tab under the Paint Tools sub-tab of the toolbox. The Paintbrush tool can also be activated from the menu bar option under the Texture > Paint Tools menu. When selected, the tool also auto-selects a Tip allowing you to begin painting directly into the active image map, defined by the selected image in the Shader Tree with the small paintbrush icon next to it (paintbrush). Simply select a different target layer if you wish to paint onto a different layer. You may also select different Customizing Paint Tools and additionally add Ink and Nozzle effects (see Customizing Inks and Tablet Nozzles) to the paintbrush to further customize the way the brush applies to the surface. When selected, the associated attributes display in the Properties panel.

Nozzle Panel

Paintbrush

Interpolation Step

Generally, paint strokes are not a continuous lines, but a series of dots or dabs placed on the image canvas. This option defines the distance between each dab as a percentage of the brush size. By default, this value is set to 5%. So for an 80 pixel sized brush, dabs are placed every 4 pixels (5% of 80 = 4). You can increase or reduce this value for a variety of effects. Increasing it toward 100% produces individual dots, rather than what looks like a stroked line.

Curve Constraint

The Curve Constraint option allows you to use pre-drawn curves, either Spline (see Adding Curves) or Bezier, and then constrain the brush strokes to the curve when painting, producing a very smooth, controlled and repeatable result. It works by having the curve element in the background layer (visible, but not selected). Then the Curve Constraint option is set to either Background 2D or Background 3D mode. Once set, any paint strokes into the canvas near the curve constrain to the nearest curve position.

The None option disables the constraining, the Background 2D projects the curve from any orientation onto the surface through the viewport and the Background 3D option constrains the stroke to the curves position in 3D space, only affecting surfaces that are within close proximity (defined by the brushes size).

Blend Mode

The Blend Mode defines how the strokes blend into the existing canvas. The default Normal setting applies opaque strokes (as defined by the Opacity option) over the top of the existing canvas. The alternate options works in the same respect as the layer blending options documented with examples on the Layer Blend Modespage of the documentation.

Opacity

This value determines the transparency of the brush tip, in turn affecting how opaque the paint generated by the brush is. Values under 100% reduce the transparency, attenuating down toward 0% where the pixels painted are completely invisible.

Density

This value determines the amount of paint that comes out during a paint stroke. A value of 100% applies even pressure across the brush's tip, values under 100% attenuating down toward 0% gradually concentrate the paint toward the center of the brushes tip, producing a results that is similar, but different, than changing the opacity.

Attenuation Steps

This value causes the paint to fade out after the set number of steps is reached in the stroke. This setting is somewhat related to the speed with which you create the stroke as painting quickly spreads out the steps used to paint the stroke. Moving the brush slowly with this value set above 0 causes the paint to run out in a shorter stroke. This is a very useful setting to use if you do not have a tablet to paint with. Tablet users would be better suited to modulate the paint opacity based on the tablet pressure so as to have greater control.

Use Falloff

The Use Falloff option allows any of the variousUsing Falloffs to mask the application of brush strokes. Since the right-click brush sizing function supersedes the right-click function to define the falloff, ensure the falloff is defined prior to activating the tool.

FG Color

Sets the foreground color for various paint tools. You can set it through the color component on the tool properties or by clicking on the Color Picker while the tool is active.

Alpha

This option allows an alpha value to be associated with the FG paint color.

Value

You ca use this percentage to increase or decrease the overall value of the ink being applied. This value can be set over 100% enabling high dynamic range paint strokes (if your image was created with the floating point, FP, mode active, or loaded as a file that supports HDRI).

BG Color

Sets the background color for paint tools that use it. You can set it through the color component on the tool properties or by clicking on the Color Picker while the tool is active.

Alpha

This option allows an alpha value to be associated with the BG paint color.

Value

You can use this percentage to increase or decrease the overall value of the ink being applied. This value can be set over 100% enabling high dynamic range paint strokes (if your image was created with the floating point, FP, mode active or loaded as a file that supports HDRI).