I don't know if you can get it in Italy, but Simili Japon, which I bought
in London and brought home with me, was the favorite of the platinum
printers here I gave samples to. It's very fine grained, doesn't need
added size, and is inexpensive -- in London it cost about 75 cents each
for a smallish sheet.
Now New York Central Artists Materials has imported a batch of Simili
Japon. I don't know what it's going to sell for here, but for sure less
than Arches Platine. The paper, a slightly off-white color, was also
excellent for cyanotype & VDB, though not for gum (at least not without
added size).
Cheers,
Judy