Illustrator (and just about all Adobe apps for that matter) has the ability to apply the most over-used design effect of all time -- Drop Shadows (look out Drop Shadows, reflections aren't far behind). Drop Shadows are applied as live effects, meaning that if you update your artwork or move it, the drop shadow updates and moves as well.
But have you ever applied a drop shadow to an object, and then ROTATED that object so that it's upside down? Have you then taken a closer look at the drop shadow and realized that the drop shadow DIDN'T rotate? Even worse, did you ever see that problem AFTER your job was printed? What I describe happens not only in Illustrator, but in InDesign as well.
Let's take a closer look at what is happening here. A drop shadow is an effect, and is therefore applied to the overall object. The shadow isn't "baked in" to the art, and so if the art changes, the drop shadow simply updates itself to match any edits applied to the object. If you flip your artwork upside down, Illustrator (and InDesign) rotates the art and then reapplies the drop shadow to the art. The result is a drop shadow that may be set to offset down and to the right, but when the art is flipped, the drop shadow is still applied with an offset down and to the right (as seen below).
For those people who regularly do imposition, or those in packaging, this presents a huge problem, and often, these problems aren't detected until it's too late. A workaround I've seen from folks is to use the Expand Appearance command (from the Object menu), but that means the effect is no longer "live" and hence, the art can't be easily updated.
Here's a solution -- create your artwork and add the Drop Shadow effect. Then, convert your artwork to a Symbol (if you use this artwork in multiple places, this is a good idea anyway). If you aren't familiar with how to create a Symbol in Illustrator, just select your art and press F8. When you rotate the Symbol, the drop shadow will now appear rotated correctly (in the example, I've been using, rotating the symbol will mean the drop shadow will be offset up and to the left).
If you ever need to modify the art or the shadow, simply double-click on the Symbol to edit it. Illustrator CS3 makes this almost too easy.
If you're in InDesign, you don't have symbols, so this solution won't work. However, there is a solution there as well, as long as you're using InDesign CS3. Create your artwork element in a new InDesign document, add the drop shadow, and then save your InDesign file. Then, PLACE your InDesign document INTO another InDesign file where you're doing your layout. You can now rotate the artwork at will, and if you need to edit the art, do an Edit Original on the placed ID file.
Oh, and BTW, how do you like them interlocking Olympic rings? If you think I used Pathfinder to create those, think again. It's all about Live Paint baby. Maybe in my next post, I'll talk about how I created those...