Why does stain glass feel like plastic?

Answer 1

With many Tiffany lamp shades, when you tap on them using your knuckle or finger tip, it does not feel like glass. That is more evident when the shade is made of smaller glass panels / pieces. When small panels of stained glass are soldered together, the vibration that it gives off when we tap on them feels more like plastic than glass; the vibration is dampened by soldering small panels of glasses together. To verify that the shade is indeed made of glass, you can use a fork to tap on the Tiffany shade lightly. You can feel the glass tone better. If you accidentally drop the shade, it WILL break.

Tiffany stained glass is thicker. When you tap on them, you are actually feeling the stain coating. They are rolled out from a big sheet of glass initially, stained into different color and then cut into little pieces before being soldered together. Unlike plastic, they have variation and rippling surface.