Using Transparency

To produce output with a transparent background. For example, you might want to add your output to a Web page that already has a specific background color or image. Output that has a transparent background allows the background on the Web page to show through. The following devices produce a transparent background by default.

To produce output with semi-transparent colors. Semi-transparent colors are particularly useful when you want to add annotations to your output while allowing the underlying graph or map to show through the annotations. Semi-transparent colors, when annotated on top of each other, blend together (alpha blending). In the following images, the red, green, and blue circles are all semi-transparent (in this case, 50% opaque). The yellow background in the first image is totally opaque. You can specify semi-transparent colors with the RGBA color mode. See RGBA Color Codes for information.