An aluminium plate of 1, 11/2, or 2 mm thick is particularly suitable when it is used in a frame of which the filling is supposed to be minimal.
Still, we would rather advise the use of dibond 2 mm because aluminium is more vulnerable to treatments and transport. This is especially a risk for larger sizes.
The weight of 2 mm dibond and 1 mm aluminium is practically equal!
Dibond gives a classic look when it is floating in front of the wall, without a frame.