I have been making pillars for my cemetery fence and I have an inset with river rock and a femur bone. They are made from a mold and are of various materials (foam, plaster, etc.) as I was experimenting. Problem is - I put 2 layers of outdoor decoupage on them and they look really shiny, almost plastic. I am wondering the best way to make them look matte again, like bone. Before the decoupage they look great. The reason that I chose to decoupage them rather than just use a sealant is because I was trying to achieve further adhesion to the board that they are glued to. Powder? Matte spray? What would be the best thing to do here without starting over? Thanks in advance.