Pencil or pen? In the future there may not be a choice. The Sharpie brand has developed a new writing instrument called a liquid pencil . The ink it contains is made of liquid graphite, has a slightly darker shade than traditional pencils, and can be easily erased with a regular eraser. And the most surprising thing is that the ink becomes permanent after three days in contact with the air.
The contraption will go on sale in September at a price of $ 5 a pair.
