Or Lexan/polycarbonate. The necessity offends me.
Here is a sample of where my musings go:
During Christ's 1,000-year reign on earth (which by now is only a very few years distant), despite His presence such measures will still be needful, because sin will still be in the world--in everyone who survives the Great Tribulation and in everyone who is born during His Millennial reign. So, even then, stained glass windows will still need protection.