Slate slab coasters from Amazon work really well for this. Engraved a couple of these for myself, like a Taito Bubbble Bobble chip and the MOS 6502 for a frien

Slate slab coasters from Amazon work really well for this. Engraved a couple of these for myself, like a Taito Bubbble Bobble chip and the MOS 6502 for a friend. They make amazing gifts.