fishpaper An insulating paper, often fiber- or oilcloth-like, used in the construction of transformers and coils. [Historical Note: Alvin G. Sydor writes: "In 1729 Stephen Gray made the discovery of the conducting and non-conducting power of different substances. Gray found that by using woven silk served as an excellent insulator. Some years later it was found that the paper industry could provide what was equivalent to woven silk. Later it was discovered that if the paper was saturated with fish oil its ability as an insulator was much improved particularly when used in harsh environments and high voltages.I think they might have be made out of "fish paper insulation". It comes in different thicknesses. Gasket material would be a lot easier to work with. The fish paper is very stiff and strong. Now if someone could tell me how fish paper got it's name I would be very interested.