PTFE feet are quieter on glass.

The scratching noise comes from hard materials rubbing against glass. Ceramic feet are harder than PTFE, so they make more noise—think fingernails on a chalkboard but less dramatic. PTFE (Teflon) is softer and glides more smoothly, reducing that high-pitched scratch.

That said, glass mousepads are naturally louder than cloth or plastic. Even with PTFE feet, you’ll hear a soft sliding sound. Ceramic feet sound like sandpaper on glass in comparison. I’d skip ceramic unless you’re a speed freak who hates friction and doesn’t mind the noise.

PTFE wears faster on glass, but that’s the trade-off for quiet operation. Replace them every few months and you’re good.