The short answer is that it would be very good at VHF and above, and
poorer at lower frequencies. How it would compare with a metal mesh
depends on the frequency, the nature of the mesh, and the application,
so there's no simple answer to the comparison question.

To make it reasonably opaque to currents and fields, it needs to be at
least several skin depths thick. As far as I've been able to tell,
aluminum foil is roughly 0.02 mm thick. That would be 3 skin depths at
about 150 MHz; below that frequency, it would be increasingly
transparent. Above that frequency, it would have the same resistance as
a group of separated wires having the same surface area. Because it has
such a large surface area, I'd expect it to do as well as or better than
most wire meshes down into the HF range. But as I said earlier, it depends.

Roy Lewallen, W7EL

David wrote:
Is aluminium (baking) foil any good as a ground plane? How does it compare
to metal mesh?