There are several kinds of ballpoint pens
By color ⑴ Monochrome ballpoint pen: This is the most common ballpoint pen, often in blue, black, red, etc. ⑵ Two-color ballpoint pen: generally red and blue two-color. ⑶ Three-color ballpoint pen: red, blue, and black. ⑷ Four-color ballpoint pen: red, blue, black, and green. In addition to these four, there are six-color, eight-color, and…