Eh, this was odd. None of the other Aeros in the cupboard got this, but my brown hwm had a fine blue, dusty layer on it after being in storage (in the UK, in a pretty temperate climate). It hasn't damaged the leather, doesn't seem 'rooted' in the jacket- is it possibly the Renapur I treated it with reacting to something? Not worried (it brushed off easily), but curious to see what you guys think.
J.
J.