The most efficient way of using an optical illusion: Paper-metal cup


I bought a take way coffee today and it came in a strange cup.

Normally take away coffee cups have outside grips made out of some sort of cardboard type material but this special one had horizontal prints going perpendicularly through the normal grip structures.

This creates an optical illusion which makes the cup look like a metal cup with a spiky solid mesh grip.

With this cup, dropping becomes almost impossible, your coffee heavily and steadily stays in your hand whatever happens to you.