First the good - this is a very nice filament. Prints easily and has a copper shimmer out of the printer, which leads me to the bad. Copperfil looks very matte off the printer where this really doesn't. I don't believe this product contains any metallic copper. In fact I'm pretty sure of it. A 2m length of this weighs 6g, which is exactly the same as 2m of regular PLA. If it had any significant amount of metal in it it would be significantly heavier, like 3 times heavier for the real stuff. Trying to sand and polish this leads nowhere, as does trying to oxidise it. If there is any copper here (as opposed to coppery coloured plastic) there's not enough to make this what it's supposed to be.
Nice copper coloured filament, but don't buy it thinking it's a cheaper version of the real thing - it isn't.
Unfortunately I have rolls of the aluminium, brass and red copper to try too. As I do I'll report on those also.