Paper Circuits
What is a paper circuit?
A paper circuit is an electronic circuit built on paper instead of a circuit board.
Conductive tape
A trace is a path that takes the place of wiring. Paper circuits use conductive materials like copper type or nylon tape as a substitute for wires to connect components. If you're working with copper tape, keep in mind that it's only conductive on one side, whereas nylon tape is conductive on both sides.
Working with LEDs
LEDs (light-emitting diodes) only allow current to flow in one direction so it's important to pay attention to which side is which so that your creation lights up. The positive side of the LED is called the "anode" and has a longer "lead," or leg. The other, negative side of the LED is called the "cathode" and has a slightly shorter leg.
The current flows from the anode to the cathode. If your LED is reversed, it will block the current flow. All you have to do to fix it is flip it around.
