They are just smooth. The only 'other'plastic rollers I can think of are those ones with the little teeth in them(they don't give a smooth set at all, your hair dries with ridges in it ...but they do dry fast). And the plastic 'mesh' rollers(way different that the wire mesh that I use). I think the name 'magnetic' comes from the fact that when your hair is really wet it 'clings to the roller?