I did run test prints on the Atlex five different metallics offered in their sample pack today. I'll disqualify myself from being able to judge three of these papers, other than to say that I hate them deeply, and can't imagine what kind of photographic content one would choose to print on the Pure Silver, Pure Gold or Moonglow. These papers offer basically the appearance of any paper you have in mind, but only after spray painting it with metallic silver or gold model airplane paint. The inkjet print appearance follows that idea quite neatly, in my mind. Truly awful, if one is expecting an image to render in any linear way as it would with the papers we normally discuss here - but possibly interesting to the artist creating something outside the box. I'll certainly accept the premise that there is no other way you'll achieve this look without using these three Atlex papers, Pure Silver, Pure Gold or Moonglow. As a side note, the Pure Silver and Pure Gold exhibited heavy ink pooling and coalescence of ink passes until I dealt with the driver settings on our 4900. In summary I now understand why Atlex posts no ICC profiles for these three papers: Worrying about custom ICC profiles for these papers would be like insisting that you measure a tree trunk with a micrometer; marking it with chalk; and cutting it with an axe.
The Atlex Chrome Glossy is a nice paper and will be fundamentally familiar to anyone who has tried the Red River Polar Metallic, the Breathing Color Vibrance Metallic, or the Moab Slickrock - and probably others. I like these papers and what they can offer to the right image.
The 5th remaining Atlex paper is the Metallic Pearl, and this occupies an interesting slot that is between a pearlescent surface - say Canson Baryta Photographique, Ilford GFS or Museo Silver Rag- and a metallic surfae. This paper, the Pearl, is the most interesting to me in that I'm not personally aware of any similar material. That said, I'd probably choose the Chrome Glossy, the paper that most resembles what I now regard as familiar in character, when I want that look.
As an aside, Red River today announced that their Polar Metallic will be available in 300 gram/square meter weight, as of next week. RR tells me it's the same surface, so any ICC profile that was good with the original Red River Polar Metallic 255g material will still be good.
Another aside: I did create a Z3200 Preset for the Breathing Color Vibrance Metallic, using the HP Glossy media (not sure of the exact vocabulary in the HP driver) with standard ink limits and platen. Initial impression is that there will be no reason you can't make this paper style work on a Z machine.
Best to all,