Discuss the cracks from space debris at the ISS:
HHH: What is it? Only 10 cm of glass. I thought it should be more, but it was dangerous.
WOW: There is a layer of discolored blue isolant, not a scratch.
Zzzz: then it had to be glued on both sides.
www: Stay in place, you have already left, where do you know what is on the two sides of the isolant?