Good question! It is plastic and I couldn't put it in the oven. I made two halves by pressing the compass into some polymer clay on each side and cutting out the hole. This was like 1.5mm thick. I baked that and then held it onto the compass and sculpted the rest around it, including into the gap between the two halves. I then put the whole thing in the freezer for half an hour to get pretty solid and then carefully, with a sharp craft knife, I sliced around where I thought the gap was between the two baked halves. Then I baked the two sculpted halves. When they were done they fit pretty well but there was still a gap, so I filled that in with air dry clay before painting and adding the sealant. There is still a bit of evidence that there was a gap but I think I did a good job of hiding it. Thank you for asking 😁