Vector halftone shadowing for dimension in 2-D space.
The beauty of vector illustration in branding & identity work is its clean lines and the mathematical maintenence of these lines at various sizes—large & small—with no loss of quality or integrity. The supposed drawback that finds many designers still doing illustration & logo work in Adobe Photoshop (ewww!) is the ability to add faux-dimensionality with the shiny baubles & fools gold of the design world; namely culprits such as bevels, drop-shadows & lens-flares. You will need Photoshop, but not in the manner most often utilized. I want to show a very brief explanation of how to RDQLUS achieves the effect of dimension in a flat, vector illustration space—giving all the drama, yet none of the restrictions of those wicked pixels or resolution concerns in the end.
1. Starting with a vector illustration, a apply a gradient fade from white to black along the edge you wish to show dimension. *Note: a "rich" black will offer the best results.
2. Copy/Paste your illustration into a new Photoshop file. Make sure that the color profile is switched to "grayscale," and then shift it once again to "bitmap." Play with the settings here to get the desired effect—[Command-Z] (Control, for the PC bretheren) is your friend. Save your file.
3. Place the bitmap into Illustrator and use the "tracing" tool—the advanced options are best for desired details & results.
4. Since this effect adds dimension you'll see that it works best when the main subject is lighter than the base color to give the illustrated illusion of shadows, though it is 100% vector.