What makes a design classic?

IT TAKES time to become a classic. If there's one definition of this abused term, it's about resisting the inevitable ebb and flow of taste and fashion. Classics can't be invented, they evolve. They have to win approval and slowly acquire value.

The second order question that follows is how do you design a trademark (a term I much prefer to the pseudo-professional "logo") that resists these chronic depredations? The answer has something to do with clarity in conception and consistency in execution.

The great trademarks were always simple ideas. Coca-Cola was derived from the copperplate handwriting of the Atlanta company's first book-keeper. The myth of Ford's blue oval concerns Henry himself. IBM's was designed to a stern brief, in this case from the designer to the client: "You would prefer neatness."

The Mercedes star was drawn on the side of a house in south Germany by Karl Benz in the 1880s to illustrate the engineer's belief that from that spot one day a star would rise, as it indeed did.

These great trademarks may be consistently refined, but they will never be replaced: they have too much value and meaning. They are just too good. Real classics. In Italy, after 25 years of flirtation with trapezoidal Seventies modernism, Fiat is returning to a version of its century-old original.

Campbell's had all of this and it seems odd to dispose of so expensively groomed an asset. Just as the blue oval immediately connotes good-value, no-nonsense, reliable automobiles, so Campbell's means quality tinned soup.

Of course, Andy Warhol recognised the iconic significance of this American heraldry and, while his intent may have been sadistically ironic, the honour he paid a soup's trademark only increased its worth. Like Ford, Coke and IBM, Campbell's trademark had acquired huge image capital, that mixture of associations and expectations which successful products have.

Current fashion in commercial art, a term I much prefer to "graphics", tends towards a restless neophilia, a stubborn lack of clarity and incoherence. Time again provides a test: the most successful product designs have been the simplest, the Volkswagen, the Vespa, the Biro. Products so complete that only refinement is possible.

Will the new Campbell's trademark become a classic? Of course, only time will tell, but I wouldn't be surprised if one day they brought back the original.