Adobe illustrator 10 사용자 설명서

In Illustrator, you can add transparency to your artwork in a variety of ways. You can vary 
the degree of transparency of an object, a group of objects, or a layer from 100% opacity 
(completely solid) to 0% opacity (completely transparent). When you decrease an object’s 
opacity, the underlying artwork becomes visible through the surface of the object. 

Using commands in the Transparency palette, you can also create special effects, 
such as knocking out underlying colors, or creating graduated transparencies or blends. 
For example, you can use the Knockout option in the Transparency palette to have an 
overlapping stroke knock out the color of the underlying fill.

Filled circle and overlying stroke without Knockout Group option (left) and with Knockout Group 
option applied (right).

Transparency is such an integral part of Illustrator that it’s possible to add transparency to 
your artwork without realizing it. For example, applying effects and styles may introduce 
transparency into your artwork. It’s important to be aware of when you’re using trans-
parency because you need set some extra options when printing and saving transparent 
artwork. (See 

By default the Transparency palette acts on objects, but you can also use it to create 
unique transparency effects at the group or layer level.

If you simply select objects and change the opacity setting, the selected objects’ opacity 
will change relative to the others. Any overlapping areas will show an accumulated 
opacity.