Hi all, first post here and I have a question about tinned copper. I bought myself a variety of tinned copper canele molds, and the cheapest ones (very cheap for copper), have a tin lining which looks a bit odd to me. It has virtually no shine to it, and looks almost like frosted glass. I've attached a photo to show what I mean. The top most mold is from Dehillerin in Paris, the middle is from De Buyer, and the last is the cheap-o. Does anyone know if this is normal? Thanks!