2008

You change the active sub-object level using the Modifier Stack display on

page 7427 on the Modify panel.

Subtractive Opacity

Sphere on the right uses subtractive opacity.

Subtractive opacity darkens colors behind the material by subtracting the

material's colors from the background colors.

If you simply want to reduce the apparent opacity of a material, while

maintaining the color values of its diffuse (or mapped) properties, use

subtractive opacity.