Insulated wires that look a lot like bare metal are quite common, e.g. in electromagnet coils. https://en.wikipedia.org/wiki/Magnet_wire https://en.wikipedia.o

Insulated wires that look a lot like bare metal are quite common, e.g. in electromagnet coils. https://en.wikipedia.org/wiki/Magnet_wire https://en.wikipedia.org/wiki/Magnet_wire The insulation melts away where it comes in contact with hot solder, so it's very easy to work with for hand-wiring projects.