When working on ads for a client, the first thing we end up needing is the logo. We addressed the problems in getting insufficient resolution for print-work in a previous post, so what I want to cover today is an even better solution–one that has no resolution at all–vector artwork.
“Vector” means that the artwork is described by mathematical formulas describing the lines, curves, colors, gradients, etc. Because it is not defined in terms of a defined grid of colored blocks (pixels), this artwork can be blown up as large as you want and still look sharp. For most graphical work, like corporate logos, this is the best format to use, especially since the file size of these pieces is usually smaller than high-resolution bit-map (made of pixels) artwork. Vector artwork can then be scaled to use online, in print ads, and even on billboards. A little file goes a long way!
Where vectors run into trouble is when they’re trying to define more illustrative or photographic treatments that have subtle blendings of shapes and colors, soft drop shadows and out of focus elements. In those cases, it just makes sense to go with the raster art (another name for bit-map). There are some talented artists out there that can reproduce almost anything as a vector drawing, but the level of detail ends up making the file size no smaller than the bit-map’s, and it still doesn’t have the same noisy texture that makes so many photos and photo-illustrations come alive.
So you know we want vector logos, but how will you know them when you see them? A reliable sign is the suffix on the file name. If your file’s name ends with “.eps” or “.ai”, then it’s very likely to be vector in the form of an “encapsulated postscript” file or an “Adobe Illustrator” file, both of which work equally well. Please note that an .eps file created by dropping a low-resolution web logo in an Illustrator document and then saving it as an .eps doesn’t work and it defeats the purpose. If all else fails, get in touch with your graphics department. They usually know what they’re doing. 
- j
