For a short while, these tops were, um, tops. The variety of available designs was astounding, and ensured that whatever pattern you chose, the chances of running into someone with the same shirt were slim. They were the perfect expression of the flamboyant pseudo-individuality that gripped the country in the seventies.
Nik-Nik is probably the best remembered polyester shirt maker, but there were many others. The best of these was Kenington. While other shirt manufacturers were printing postcards and splashy patterns on their shirts, Kenington obtained the rights to reproduce the Disney characters. Some Kenington shirts were printed with scenes from Disney films, while others featured Disney characters placed in famous paintings (for instance, Minnie Mouse as the Mona Lisa).
Polyester shirts might have continued as a fashion trend if not for two inescapable facts: they felt bad and smelled awful. The feeling of a polyester shirt against your skin is hard to describe. It's something akin to wearing a wetsuit smeared with plastic lard.
Odors become trapped in the fabric and no amount of washing will remove them. The positive ionic charge of the fabric acts makes dirt cling more fiercely to the fabric than it does to soap. As time goes on, the shirts smell worse and worse, until that acrid, rotten smell, so often associated with polyester shirts, is inescapable.
Soon, all but the most hardcore, coke-snorting, zodiac-inquiring, singles-disco males had discarded their polyester shirts. Shortly thereafter, the shirts were stereotyped to this group of people, and the polyester shirt went the way of all fashion.