The pen is a marvellous invention, but when it has done its job it still ends up in the garbage. One more non-recyclable item journeys to the landfill. In the US, 1.6 billion meet that fate each year. Recycling pens poses big problems. Even though a good portion of a pen is plastic, it is usually several different kinds of plastic, usually contaminated with a bit of metal or an ink core or some other materials.