What causes the dark blue effect in fancy glass doors?

Question

https://i.imgur.com/gpi3zZR.jpeg – here’s a picture

I can’t explain it super well, but on fancy glass office doors, usually in sky scrapers, the side of them have a dark blueish almost black tint to them, but not the rest of the door, I’m curious as to why this is.

In: Engineering

Answer 1

It’s probably laminated glass, with a layer of heavy duty vinyl glued between two pieces of glass. That plastic sheet can be printed, either for a design or tinting or just a mark to let you know there’s a piece of glass in front of you.