I want to know the answer to the following question:
What was the plate used for anti-aircraft proximity fuses in World War II made out of?
All the background I'm provided with is that "The Centralab Division of Globe Union submitted a proposal which met the requirements: a ceramic plate would be screenprinted with metallic paint for conductors and carbon material for resistors, with ceramic disc capacitors and subminiature vacuum tubes soldered in place.". Is that enough to answer the question?