I made new Tiles for sudoku that has 2 colors. This way you can use for the Puzzle then use a second color to work it out. I use black to setup, and white to work it. Mine currently works in [https://makerworld.com/en/models/130456-sudoku-board-tiles?from=search#profileId-141522](https://makerworld.com/en/models/130456-sudoku-board-tiles?from=search#profileId-141522) board made by KobaRiley. My tiles are like his that are bent on top and back.