Carbon black

Carbon black is a powder of tiny carbon particles, typically about 10 to 100 nanometers across, fused into short branching chains. It's nearly pure carbon, but unlike soot from a fire it's made on purpose, under tight control, so the particle size is consistent.

Most is made by the furnace process. Heavy oil is sprayed into a hot flame of burning gas that has too little air for the oil to burn completely. Instead of turning into carbon dioxide, the oil cracks apart and its carbon atoms clump into particles. Water sprays stop the reaction within a fraction of a second, and the black smoke is collected in large bag filters. Changing the temperature and timing changes the particle size, and with it the shade and behavior.

About 70% of all carbon black goes into tires, where it strengthens the rubber and makes them black. In a TV it has three jobs. It's the pigment in the black matrix of the color filter, the black in the mold compound that packages chips, and the conductive filler in the rubber pads under each key of the remote control. Press a key, and its black pad bridges two contacts on the board.