I think lasers are pretty wack when you think about them through this lens. A small, wand-like object in your hand can make light appear from seemingly nowhere. If it’s powerful enough it can set things on fire or blind people. Not to mention larger ones like laser cutters or the LLD, used to destroy missiles midflight. Thats sure to blow some feudal peasant minds
Hmm I am not sure specifically the printing part would be that magical. After all you are just squeezing a material through a nozzle and moving the nozzle to make a shape which is conceptually easy to understand. However translating words into the 3D printer head moving to creat that shape would be the magical part