The prints are most likely Fujiflex. I printed on Fuji Supergloss for years until digital enlarging took over the market. Now I occasionally get prints on Fujiflex. Tried to emulate this with my z3100, the papers are close but the ink just sits on top and doesn't have the same gloss. Also tried on Epson printers as well. I think it's the difference between the pigment on the paper (inkjet) and dyes in the paper (Fujiflex, etc.). Don't think they will ever be the same looking.
People always ask if my Fuji Supergloss/Fujiflex images are internally lit lightboxes, the white of the paper has a pearlescence to it that just glows. I think the "paper" is a polyester base similar to Ciba/Ilfochrome papers. There are quite a few printers using this paper around the world.
On a side note, gotta hand it to Peter Lik, I've never heard of him but apparently he's the "most awarded photographer in history". They forgot to mention all the awards are from one place, the Australia Institute of Professional Photography. Don't get me wrong, it's competent work but there are 1000's of photographers shooting the same sunsets, sand dunes, etc. He belongs in the Art Wolfe, Dale Chihuly "art" circle. Maybe they should all get together and form a supergroup.