There are thousand of females working as gravure idols in the world, but this list highlights only the most notable ones.
There isn't a rule for regular model, even in playboy they still considered models, maybe in Japan it's different? Many popular female idols in Japan launched their careers by starting out as gravure idols.
Gravure model is called gravure model in japan and asia bcus regular model in asia dont really do that.
Gravure idols, in most cases, emphasize their sexual attractiveness and often model in swimsuits.