sportback wrote:
There are two basic principles here - the painted dials, where the luminous material is applied to the surface of the dial, and the 'sandwich' dials where the numbers and minute markers are cut out of the metal plate which forms the visible dial (behind the crystal). Behind this is a second metal plate with recessed areas where a thick luminous paste is applied - the areas corresponding to the cut-outs in the first metal plate - thus 'sandwiching' the luminous material between the two metal plates.
Does this help?
Take a look in the gallery section where I've posted an example.
I always thought it was a top layer of metal with the numerals cut out (so far so good) with a plate of luminous material (plastic or something) sandwiched below it, with another plate of metal below that! Shows I really do know nothing about Pannies!