I bought a shirt a couple of days ago from a reputable UK high street retailer (Marks & Spencer) which is labelled as being 100% cotton. It said this on the packaging and on the tab stitched into it. Today I was in another shop and spotted what appeared to be the exact same shirt. It was absolutely identical apart from the manufacturer label stitched into it. The same pattern on the fabric, the same buttons, the same cuff details, the same placket, the same shape collar, etc. I assure you, it wasn't just similar, it was a completely identical shirt. However, it was labelled as being 60% cotton and 40% polyester. So, how likely is it that a factory somewhere is weaving the exact same cloth with the same coloured yarns/threads and then another factory is cutting and stitching them the exact same way, except some batches are woven with pure cotton and others with a mix? Is it possible that both shirts are made from the same material, it's just that one of the shops has been lied to by the real manufacturer (probably a far-eastern factory), and this deception is being passed on to the customer? How can you be sure a cotton shirt really is all cotton?