The Secret Behind Unbreakable Glass! Laminated glass is made by sandwiching a thin layer of plastic - usually polyvinyl butyral (PVB) - between two sheets of glass and bonding them together under heat and pressure. The science behind it lies in how the plastic interlayer changes the way the glass behaves when stressed. Unlike ordinary glass, which shatters into sharp pieces, laminated glass cracks but the fragments stick to the plastic layer, reducing the risk of injury and keeping the sheet lar