Opacity Sets the transparency of color you apply. As you paint over an area, the opacity does not exceed the set level no matter how many times you move the pointer over the area, until you release the mouse button.

Airbrush Simulates painting with an airbrush. As you move the pointer over an area, paint builds up as you hold down the mouse button.

Flow Sets the rate at which color is applied as you move the pointer over an area.

Mode Sets the method for blending the color you paint with the underlying existing pixels.

Auto erase Paints the background color over areas containing the foreground color.