Silicone base for glass desks.

Silicone.

Foam bases rely on friction against the surface, and glass is too smooth to give much grip. The foam will slide around with even moderate mouse movement. Silicone, on the other hand, creates a slight suction effect on glass. It sticks like a phone mount to a windshield. You’ll have to actively peel it up to move it.

One caveat: some silicone pads can leave a faint residue on glass over time, especially in heat or direct sun. It wipes off easily, but if you’re a stickler for a perfectly clean desk, it’s worth knowing.

Your mousepad shouldn’t be a moving target.