A logo is just one element in a corporate identity system, but its importance cannot be underestimated. Everything about a company its products, people, and place in the market contributes to our perception of its identity. But ultimately it's the logo, a simple combination of letters or symbols, that has the tough job: to identify a company and express its personality at a glance.

THREE CORE PRINCIPLES

First, a logo must be practical. It must work at both large and small sizes, and in black and white as well as full color. It must translate well across a wide range of media, from billboards and newspapers, to Web sites and TV broadcasts. Unlike other representations of a corporation or organization (such as letterheads, business cards, and Web pages), a logo cannot or at least should not be hastily updated or modified to fulfill sudden changes in management directives.

Second, a logo must communicate on several levels. Even if a logo is just typography (and many are), it must communicate:

Third, and most importantly, a logo must hold a quality of visual appeal that Paul Rand once described as "sheer pleasure." When you see it, a logo should immediately trigger a visceral reaction: communication, identification, and emotion.

Ultimate objectives aside, what really makes a logo work? There is no easy or exact answer to this question. A logo is a shorthand signature (sometimes literally) that expresses the company or product it represents. And like a signature, it has the power to impart personality, definition, and dimension.

Of course, while a great logo (sometimes called a logo mark or mark) has the power to elicit a desired emotion, it's also true that an ill-conceived or misappropriated design can trigger an unintended negative reaction from its audience. For that reason, logo design projects are intensively critiqued and meticulously researched. It takes passion and precision on the part of the designer to get it right.