Is it possible to animate 2 folds on the same sheet? As can be seen on the screen shot, I want to animate first folding the top right triangle and then along the center line of the sheet using the 2nd bigger bone. and then a third fold of the left side triangle. However when I do my second fold the whole sheet scrambles up. Some of the vertices from the two assigned grouped overlap, so I am not sure if this is the problem for blender. What is the correct way to make this work, or maybe it is just not possible in Blender?
Assign only the needed vertices (tips) for each bone as follows:



And then you should fold it beautifully.