Float (Pilkington) Glass
Definition
Sheet glass manufactured on a bath of molten tin. The tin-contact face fluoresces under short-wave UV, which lets the analyst orient a fragment and confirm float origin.
- Manufacturing bath
- Molten tin
- Diagnostic feature
- Tin-contact face fluoresces under short-wave UV
- Use in casework
- Orients a fragment and confirms float origin
- Common name origin
- Pilkington, the process developer
Common questions
Why does only one face of a float glass fragment fluoresce under UV?+
Only the face that was in contact with the molten tin bath during manufacture picks up trace tin, and that residue is what fluoresces under short-wave UV, so the opposite, air-cooled face gives no such response and the two are distinguishable.
What does confirming float origin add to a glass comparison?+
It establishes that the fragment came from flat sheet glass made by this common modern process, which is useful contextual information, but it does not by itself individualise the fragment to a specific pane; further physical and chemical comparison against a known source is still needed for that.
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