The 28 series is formed by creating a conventional glass-blown sphere and allowing it to cool, then using a blowtorch to create a hot patch on the surface. A different colour of super-hot glass is dropped into the heated exterior patch, creating a vacuum inside the original sphere, to which only the very hot, recently introduced glass can respond in a controlled implosion.
The result is a slightly distorted sphere with an interior landscape of satellite shapes, including an opaque milk glass diffuser that houses the bulb.
The ‘s’ designation in this variation of the 28 refers to it being surface-mounted, with transformers mounted remotely. This surface light has a discrete 5.5cm diameter mounting plate designed to be mounted on walls as well as ceilings.
