[old_tv_nut]

The Trinitron grille wires could not warp because they were under tension. If you managed to really overheat them to the point they lost tension, they would become loose, like strings that are too long for the size of the frame. It was not only the thick glass that made Trinitrons heavy, but also the grille frame that was sturdy enough to maintain tension, just like a piano frame. Self-supporting shadow masks were not under any tension, just had enough strength to maintain their own shape due to the compound curve (same principle used to make auto bodies, where you never find a flat surface).