How to Do Everything with Adobe Illustrator CS

Overview

A fully transparent object is one that is completely see-through, like a clean, untinted window. At the other end of the scale, a fully opaque object is one that you cannot see through at all. Partial transparency (also called partial opacity ) allows an object to be made partially transparent, like a tinted lens. In common usage, applying transparency in Illustrator really means applying partial transparency, a filter that alters the density or color of an object.

In Illustrator, transparency is applied in degrees, ranging from 1 percent (almost completely opaque) to 99 percent (almost completely invisible). An object with 0-percent transparency is opaque, and an object with 100-percent transparency is invisible.

Transparency is used for objects that cover other objects. For instance, a tinted plastic sheet in Figure 17-1 tints the fruits it covers. However, the pricing signs are on top of the transparency object, and are therefore not affected.

Figure 17-1: The screen covering some of the fruits has partial transparency.

Objects with partial transparency affect objects stacked below them. An object stacked beneath a transparent object will be partially visible.