They’re made from potato starch, which results in a 100% biodegradable chalkboard, believe it or not. And because they’re stickers, they’re ideal for small spaces–no jutting out from the wall. You might say they’ve got a lovely little actual footprint to go with that little carbon footprint.
These erasable stickers work with regular chalk (which yes, you’ll have to clean up as the chalk dust accumulates), but that’s pretty much the only “regular” thing about them. -Mir