DIY: what material to use as DIY shim seat post? Seat tube shim adapters are quite expensive, what kind of material do you recommend as a shim?

I have seen in a thread some guys talking about home made shim:


paper tape
alloy drink can as a shim (aluminium or steel?)
Thin and quality paper/cardboard


Which one would be the best?
Definitely alloy drink can or other thin sheet metal as it is not compressible and is not affected by water, oil or grease.