Printer was already invented long time ago
Nobody in here understands what OP is saying
While I agree that most of the things mentioned in this thread are innovations and not inventions, I don't agree with the idea that a 3-D printer is an innovation of the printer.
The core functionalities and premises are not the same. The printer that was invented ages ago is transferring digital information onto an existing tangible item. A 3-D printer is essentially completely manufacturing products.
If it is an innovation, it's an innovation on some production machinery moreso than it is an innovation on a printer. A printer is just what someone decided to call it.
Long-story short. It probably still is technically an innovation. Just not of a printer.
Edit: After further thought I think a 3-D printer is an invention. Considering factory machinery is mostly just assembling parts created via some other process and a 3-D printer actually creates these parts from some composite material, I'm gonna classify it as an invention. Is there anything else that does that or something similar?