The most impressive glowing plates I've ever seen were 35T triodes. The tantalum plate would (properly) be run so hot (white!) that you could see the shadow of the grid wires through it, illuminated by the filament. I believe the glass was called 'Nonex': it was heat resistant and low RF loss. You sure as hell don't get the beauty of glowing bits with solid state - well, not for long! 73 Peter G3RZP