Actually you can use a mix of acryllic sealer sprayed into a small dish (so it condenses) and mix in pearlex powder to paint metallic. It’ll stick to most anything (though you may want to try something as a test run first.) And ventilated area required.
I’d imagine if you got decent sizing you could silver leaf it too.
The first would be a more brushed finish. The second far shinier.
Of course both of the above would indicate acryllic not sticking on its own – which it might. I’ll be certainly letting you know quite shortly 😉