> Wait but then why is one physical iPhone identical to another physical iPhone of the same model? Hard materials are easier than soft materials in some ways.

> Wait but then why is one physical iPhone identical to another physical iPhone of the same model? Hard materials are easier than soft materials in some ways. If you lay a soft fabric out before cutting, is it slightly folded, perfectly flat, taut? It will all make a difference. Moulding plastic or cutting a hard material like aluminium is more amenable to tight tolerances since you can use the same mould over and over, use the same cutter and the material doesn't flex, stretch or change in any significant way.