Thanks to both of you cspear and bagginsbill : I guess the "V4 skin realism kit" is the right product. I read it helps you to control "oiliness" as well as bump map, etc. If I get it for Xmas I'll tell you more. I was meaning that some characters are by far too shiny and if some artists provide both shader and no shader mats ( I'm thinking of Subgraphix for instance ) many don't ; the result of this is unrealistic oily characters. I know blinn is the answer but it's a lot of work...and a lazy guy like me was dreaming of an easier way to reduce or get rid of oiliness...
Again many thanks. Merry Xmas + a very prosperous New Year