But before we get there, let's first explore a few ways to easily add some interesting border effects to placed images in Illustrator. Yes, we'll use the Appearance panel to do so, and naturally, we'll save our appearances as Graphic Styles, so that we can easily apply them to photos and artwork at will.
As you may know, Illustrator can apply fill and stroke attributes to vector paths, but an image in Illustrator isn't a vector path at all. As such, we'll need to employ a few "tricks" to allow us to accomplish our goal. I've actually covered parts of this concept in a previous post, but in this technique, we'll take things a step further. To make this tutorial even better, I'm going to use images of David Blatner that somehow ended up in my iPhoto library :)
1. Place an image into your document.
2. First, we'll add the inner glow that appears within the border. With the image selected, click the Add New Fill button in the Appearance panel. Specify a fill of White.
3. At this point, we don't see anything happening because we've applied a fill to an image object. We need to generate a path so that Illustrator has somewhere to apply the fill. With the white fill highlighted in the Appearance panel, click on the Add New Effect button at the bottom of the Appearance panel and choose Path > Outline Object. Now, the white fill, which appears above the pixels in the object's stacking order, should be visible.
4. Obviously, the white fill hides the photo, so in this step, we'll fix that. With the white fill still targeted, click once again on the Add New Effect button and choose Stylize > Inner Glow. Specify Multiply for the Mode, change the color to Black, set the Opacity to 50% and the Blur to 3 pt. Use the Edge method and click OK to apply the effect. You should now see the lovely inner glow, but the white fill still obscures the view of the image. Click on the word Opacity that is listed in the white fill and change its Blend Mode to Multiply. At this point, the white disappears, leaving the photo and the inner glow intact.
5. Add a new fill to the image, once again specifying a color of white. This will be the white matte that appears between the frame and the photograph. With the new fill targeted, click on the Add New Effect button and choose Convert To Shape > Rectangle. Use the Relative option and specify both Extra Width and Height to 12 pt. At this point, the fill appears ABOVE the image pixels, so drag the fill down so that it appears beneath the Image Pixels in the Appearance panel.
6. With the bottom fill targeted (the one we just created in step 5), click on the Duplicate Selected Item button at the bottom of the Appearance panel. You now have two white fills that have a Convert To Shape effect applied to them. Target the bottom-most fill and change its color to a gradient. I loaded Illustrator's Metals collection of gradients and chose Polished Brass, but you're free to choose whatever works best for you. With the fill still targeted, click on the word Rectangle to edit the Convert to Shape effect. Change the Extra Width and Height values both to 24 pt and click OK.
7. Because I wanted a beveled edge to my frame, I added a 3D effect as well. With the bottom-most fill still targeted, click the Add New Effect button and choose 3D > Extrude & Bevel. From the Position popup menu, choose Front to view your fill head on. Specify Rounded for the Bevel and click OK. Your Appearance panel should match the screenshot above.
8. With the image selected, click the New Graphic Style button in the Graphic Styles panel. You've now defined a complex border that you can apply to any artwork, and any placed image. Joy!
EXPLORING THE PATTERN BRUSH
OK, adding fills and strokes and changing their appearances may be great, but they are obviously limited. Customized borders are certainly more complex and have to incorporate intricate artwork. This process is usually a tedious one and requires a lot of work, especially considering that each time you change the size of your frame, you need to adjust your artwork. That is, if you don't use Pattern Brushes. And don't get caught up in the name "brush" -- because you can apply a pattern brush to any path.
Admittedly, defining a pattern brush isn't a piece of cake. A pattern brush is made up of anywhere from 1 to 5 different pattern swatches. But if built right, you can end up with a border or a frame that can be scaled or adjusted to any size or shape instantly. If you need some help, Illustrator does its part by providing you with a few you can use. NINETY of them, actually. You can access these directly from the Brushes panel -- just click on the Brush Libraries Menu button at the bottom of the Brushes panel and choose Borders.
Using a few of the sample pattern brushes that Illustrator ships with, I was able to create a few interesting frames for my collection of David Blatner photos.
Of course, the reason why Illustrator ships with so many sample brushes is so that you can reverse engineer them, learn how they were created, and make your own. It's easy to reverse engineer a pattern brush. Once you've added a pattern brush to your Brushes panel, drag the brush out to a blank area on your artboard. Illustrator will create all of the pattern tiles that were used to define that brush. You can then see the pattern tiles, mess with them on your own, and create your own.
To modify the settings of a pattern brush, simply double click on the brush in the Brushes panel to open the Pattern Brush Options dialog box. What makes a pattern brush special is the fact that it can be made up of up to 5 different pattern tiles, which are used automatically, depending on the geometry of the path (inside corners, start, end, etc), and that it can automatically adjust itself to fit your path. You'll even find that pattern brushes automatically bend to fit the contours of curved paths (try them on circles and ovals!).
I've personally used pattern brushes to help apparel designers create lace trimmings, zippers, and other elements. Remember that you can use pattern brushes on both open and closed paths.
There is one thing to note. It isn't easy to apply pattern brushes to images. You can technically apply them by adding a stroke and then choosing the Outline Object effect for that stroke, but the borders don't "clip" to the image. An apparent bug in Illustrator also make it impossible to add a pattern brush to a mask, so if your image is masked, that won't work either (as you soon as you apply the brush, the mask contents are revealed). In my examples above, I actually created a separate rectangle shape and applied the pattern brush to the rectangle, not to the image itself.