[gruez]

I don't know about you, but most (all?) of the screw caps I've seen are metal, not plastic.

[pyrale]

For alcohol, that's true, but most cheap wines use plastic caps around here.

[worik]

Here (New Zealand) all wine at all price points, have screw caps

[klyrs]

The ones I get are aluminum with a plastic gasket. Which is less plastic than a plastic cap, but not zero.

[eikenberry]

I think the parent was commenting on how screw caps were better than the plastic "cork" style as well.