Brush Settings

Painting needs paint brushes and Blender provides a Brush panel within the Toolbar when in Weight Paint Mode.

Brush

In the Data-Block menu you find predefined Brush presets. And you can create your own custom presets as needed.

Radius F

The radius defines the area of influence of the brush.

(Size Pressure)

Adjusts the radius based on the stylus pressure when using a Graphics Tablet.

Strength

This is the amount of paint to be applied per brush stroke.

(Strength Pressure)

Adjusts the strength based on the stylus pressure when using a Graphics Tablet.

Use Falloff

When enabled, use Strength falloff for the brush. Brush Strength decays with the distance from the center of the brush.

Weight Ctrl-F

The weight (visualized as a color) to be used by the brush.

Using Ctrl-RMB you can set the weight to the value that's under the cursor.

Direction D

Brush direction toggle, Add adds weight value while Subtract removes weight value. This setting can be toggled with D.