Glass Bottles: The secret of the bottom bumpsA clever factory trick that prevents sudden shattering.

From the show

Why it looks like that

Understanding the true purpose of knurling reveals the hidden ingenuity of everyday packaging. Those familiar textured rings on glass containers are widely assumed to provide grip on slippery surfaces. In reality, they serve a critical role during production. By minimizing surface contact on cold metal conveyor belts, this design allows freshly molded, red-hot containers to cool down safely without cracking from thermal shock.