Liquid glass is poured over a bath of liquid tin where it floats on top, gradually cooling until it can be lifted off, annealed to prevent cracking, cut and packaged.
Also, this all has to be done without oxygen, because tin dioxide will stick to glass
Oh! Well how about that. I was so sure it was true, over a long period of time, but I just looked it up and lo and behold you’re right. I’m learning a lot in this one thread