Adobe Illustrator CS5 : Understanding Appearances (part 2) - Targeting Attributes, Applying Multiple Attributes

Targeting Attributes

Upon closer inspection of the Appearance panel, you’ll notice disclosure triangles to the immediate left of the Stroke and Fill attributes. Clicking these disclosure triangles reveals an Opacity setting that lets you control the opacity of an object’s stroke and fill independently (Figure 8). In fact, a single path contains three Opacity settings by default: one for its stroke, one for its fill, and one for the overall object. When you apply an Opacity value to a single attribute, you’re targeting that specific attribute. And in case you were wondering, yes, it’s certainly possible to apply a 50% Opacity value to an object’s fill and also apply a 50% Opacity value to an overall object (resulting in a 25% opacity, if you think about it; see Figure 9).

Since it can be confusing at times, it’s important to realize that when you click an attribute in the Appearance panel, the attribute becomes highlighted to indicate that it is targeted. If you want to target the overall path or object, click the target that is listed at the top of the Appearance panel, near the thumbnail (Figure 10). Alternatively, you can click in the empty area that appears beneath all the attributes listed in the Appearance panel.

Applying Multiple Attributes

Objects that have a single fill and a single stroke are referred to as having a basic appearance. However, vector objects aren’t limited to just one fill and one stroke. In fact, a single object can contain as many fills or strokes that your creative mind craves. An object with more than just one fill or stroke is referred to as having a complex appearance.

To add an attribute to an object, click the Add New Stroke or Add New Fill button at the bottom of the Appearance panel (Figure 11). You can also target any existing attribute and click the Duplicate Selected Item button. Once you’ve added an attribute, you can change its place in the stacking order by dragging it above or beneath other attributes in the Appearance panel. You can also remove targeted attributes by clicking the Delete Selected Item button.

You may be wondering what good two fills or two strokes do in an object, because one always covers the one beneath it. Earlier, we discussed the ability to target a specific attribute so that you can apply settings to each individually. By applying different attributes to two different fills and by applying an overprint or an Opacity setting to the top fill, you can create some interesting effects (Figure 12).

Figure 12. Combining two fills in a single object lets you create interesting effects, such as a pattern fill with an overlapping transparent gradient fill.

Likewise, you can add numerous strokes, each with different widths, colors, and dash patterns, resulting in useful borders and effects (Figure 13). Although you can certainly use more traditional methods to simulate these effects by overlapping multiple objects on top of each other, adding multiple attributes to a single path means you have just one path to work with and edit (as opposed to multiple paths). Considering the Illustrator limitation of being able to edit only a single control handle of a single path at any one time, seemingly simple edits to multiple paths could prove extremely difficult and require much time and effort. 

Figure 13. Using overlapping multiple strokes on a single object is one way to simulate stitching patterns.

Expanding Appearances

You’ll notice that you can’t target a specific fill or stroke of an object from the artboard—the only place to access this functionality is through the Appearance panel. This makes the Appearance panel infinitely important, but it may make you wonder how an object with a complex appearance will print. After all, how does the printer or export format know how to draw these multiple attributes on a single path?

The answer is that Illustrator breaks these complex appearances down into multiple overlapping paths, and each path contains a basic appearance. This process, called expanding, doesn’t happen on your artboard—it happens in the print stream or the export process.

Sometimes you may want to manually expand your appearances to access the multiple attributes as individual objects on the artboard. To do so, choose Object > Expand Appearance. Remember that once you’ve expanded an appearance, you are dealing with a group of multiple objects, not a single object anymore (even fills and strokes are separated into individual objects). Each of the individual objects has a basic appearance, and you have no way to return to the original complex appearance.