That is what I thought, but I tried 3 by me and none of them new what I was talking about. They know about the blanket, but not the board. They tell me to just mix cement with pearlight, but I know that the ceramic board is a better insulator.Check with any local fireplace installer. They usually have or can get anything you need along those lines.
Yup I'm going for the neoplaten wood fire pizza oven like thisThey do sell that stuff in a hard board. You can get Rutland's furnace cement (Tractor Supply) to seal it, and if the fire brick is going on top of it, it will pretty much mortar everything together. What type of oven are you making? Pizza style oven?