They are slate in the better pool tables, but why? Why not aluminum, or steel?
EDIT: Both of those materials are very strong, don't change their properties much in temperature/humidity variations, can be processed to have an ultra-smooth finish just like slate, can be flatter than slate, and aluminum would be lighter, I think.
EDIT2: Aluminum's density is about the same, or slightly lighter than slate.
EDIT3: Steel isn't really a good choice due to its high density. But it's durable!
And if you could build a table to support its weight, you wouldn't have to worry about damaging it.
EDIT: Both of those materials are very strong, don't change their properties much in temperature/humidity variations, can be processed to have an ultra-smooth finish just like slate, can be flatter than slate, and aluminum would be lighter, I think.
EDIT2: Aluminum's density is about the same, or slightly lighter than slate.
EDIT3: Steel isn't really a good choice due to its high density. But it's durable!