I made a obelisk grave stone out of a dollar tree Styrofoam cooler, poster board, drylok, wood putty and glue. I flipped the cooler upside down and cut out the pasteboard's and glued them together to form the top. I used the wood putty to fill in all the cracks. I put about three layers of drylok to cover the whole thing. I painted it by tea staining, then adding some white. I think it turned out pretty good for what was used.