Written in ballpoint pen principle, mainly using the ball at the time of writing paper in direct contact with the frictional force is generated, so that the ball rolling in the tee with the ink or ink cartridge inside in order to achieve the purpose of writing. Ballpoint pen with ink with a different color pen writing. Nib is a small ball, the small steel ball embedded in a small cylinder-type copper bowl, after connecting a plastic tube containing the ink, the ink flow by a rotation around with the ball. Ball-point pen ink is pigment dye. Ink colors are blue, red and black, especially the most used blue ink. Past the blue ink royal blue pigment composition is salt and salt Qinglian, the solvent is oxidized castor oil, castor oil acid. Since the basic dyes are not light (light of only one - Level 2), no heat, no acid, so durability is poor, has been eliminated. On the market of "424" blue ballpoint pen and "322" in black ballpoint pen, use it to write handwriting better durability. Frequent reports of poisonous scent ballpoint pen, stationery inferior flavor contained toxic volatile organic compounds on the human body has some damage; but it has not heard of the event due to normal use no volatile organic compounds mixed with an oily ballpoint poisoning.