Adobe Illustrator CS5 One-on-One

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WORKING WITH TRANSPARENCY

TRANSPARENCY IS all about creating interactions be-

tween objects. Or put more simply, blending. Select a path, group,

or even an entire layer and then blend it with the ones behind it.

The most basic example of blending is the Opacity value in the

Transparency panel. This option lets you mix a selected object with

the stuff in the background according to a percentage—from 100,

opaque, to 0, transparent. Because I’m a shameless epicure, I draw

the analogy of mixing a yummy beverage. Suppose you have a glass

of chocolate syrup and a glass of milk behind it. If you select the

syrup and set it to an Opacity value of 30 percent, 70 percent of

the milk shows through. Alternatively, you could move the milk in

front of the syrup and set the former to an

Opacity of 70 percent. Either way, you get a

glass of chocolate milk. For a more delicious

mix, reduce the milk’s Opacity to 50 percent.

Not everyone fancies syrupy lactose. And

Opacity is just the first of Illustrator’s many

transparency options. Which is why I offer

the cheerful holiday graphic that is Figure 8-1.

Here we see examples of differing Opacity

values (labeled Normal 100% and Normal

35%) and a few of the most useful blend

modes. Like the Opacity value, blend modes

apply computations. Add x of the active layer

to y of the stuff behind it. But blend modes

employ more elaborate arithmetic likely to

frighten humanities majors, which is why

they have math-free names like Normal

(meaning no blend mode at all), Multiply

(smooth darkening), Screen (similarly smooth

lightening), and Overlay (a bit of both), all

documented in the figure.

Figure 8-1.

Normal 100%

Multiply

Screen

Overlay

Normal 35%

Snowflake balls

©

Anja Kaiser, fotolia.com/deke

ABOUT THIS LESSON

you’ve downloaded the lesson fi les from

www.oreilly.com/go/Deke-IllustratorCS5,

as directed in Step 2 on page xiv of the

Preface. This should result in a folder called

Lesson Files-AIcs5 1on1 on your desktop.

We’ll be working with the fi les inside the

Lesson 08 subfolder.

Illustrator’s Transparency panel lets you create interactions between

paths, groups, or whole layers of objects. This panel introduces the

topics of opacity, knockout groups, blend modes, and the multifac-

eted opacity mask. As you follow along with these exercises, you’ll

learn how to:

• Create a knockout group in which all grouped

paths change in unison with each other . . . . . . . page 246

• Assign an opacity mask to an entire sublayer

of path outlines to cut a temporary hole . . . . . . . page 251

• Use blend modes to create complex and exciting

interactions between layered objects . . . . . . . . page 260

• Crop the contents of an entire layer, using no more

than a path outline and the click of an icon . . . . . page 267

Video Lesson 8: Blend Modes

Blend modes and opacity setting are the mainstays of cre-

ating transparency inside your Illustrator artwork. In this

video, I’ll cover how opacity settings affect the elements

in your image. I’ll also show you how to use the variety of

Illustrator’s blend modes, which allow you to determine

how layers interact with complex mixing formulas.

To watch blend modes at work, visit www.oreilly.com/go/

deke-IllustratorCS5. Click the Watch button to view the

lesson online or the Download button to save it to your

computer. During the video, you’ll learn these shortcuts:

Operation Windows shortcut Macintosh shortcut

Hide the selection edges Ctrl+H -H

Hide all layers but one Alt-click on icon Option-click on icon

Switch between the stroke and fi ll Press the X key Press the X key

Display the Gradient panel Ctrl+F9 -F9

Duplicate an entire layer Drag layer onto icon Drag layer onto icon

Select the refl ect tool Press the O key Press the O key

Display opacity mask on its own Alt-click mask’s thumbnail Option-click mask’s thumbnail

Select the gradient tool Press the G key Press the G key

Duplicate a gradient color stop Alt-drag the color stop Option-drag the color stop

Add a fi ll to a selected object

Ctrl+

(forward slash) - (forward slash)

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Lesson 8: Working with Transparency