This is a self initiated project: one day, when I was still living in Shanghai, I decided to start keeping my used toothbrushes because the handles looked so nice and new that it just didn't feel right to throw them away.  After some time I came up with the idea of colored pens. I found some refills, made a prototype and thought up an ecological packaging (I get 6 from a single A4 sheet of recycled paper). Now all my family is condemned to use this kind of toothbrush so I can keep making more. They are all sterylized after I cut off the head part and I can produce about 10 each month. They come in blue, magenta, orange and green.