[Claudio]

Here what I got.... First of I was using the bones in one line straight (one after the other), I manage to open Mark's sample and noticed that he used two bones parallel to each other like a T shape.
Once I tried this I got half of the result I want, since the fold was stretching and deforming the thick cover, so I used another set of parallel bones about the meddle of the cover to hold it in place.
I guess I'm all set now with this... I will post a sample of what I was trying to achieve.

Thanks again.