I contacted the Xperia support asking them what type of glass the z3 front and back is made of. This was the reply I got.
Thank you for contacting the Sony Xperia support centre.
With regards to your query on the Xperia Z3 glass, please be informed that the device is using a “Gorilla II” type of glass and it has an anti-shatter film(ASF). The ASF is softer than the display glass, and thus less scratch-resistant.If the layer is peeled off the display will lose some its shatterproof characteristics. The purpose of the anti-shatter film (ASF) is to make the display withstand being dropped from greater heights.The anti-shatter film has a positive effect on the sensitivity and accuracy of the touch screen. In the unlikely event of the glass cracking, the ASF can protect against cuts.
Question is, I thought since z1 they no longer put the ASF on top of the display. Why is it back on the z3??