Built-in Mathematica Symbol

Opacity

Opacity[a]
is a graphics directive which specifies that graphical objects which follow are to be displayed, if possible, with opacity a.

Opacity[a, color]
uses the specified color with opacity a.

If an opacity a object with color c₁ is placed in front of an object with color c₂, the resulting color will be the blend ac₁+(1-a)c₂.

If red and blue with opacity 0.5 are combined, the result is purple—not black, as it would be with physical monochromatic filters. »

It may take significantly longer to render 3D graphics that involve transparent surfaces.

Graphics that involve transparency may need to be printed as high-resolution bitmaps.

On many computer systems, objects with opacity a will appear completely transparent if a is too small. »

Make a 50% transparent sphere:

Plot a see-through surface:

Overlapping translucent 2D disks: