The fluorescent pen has fluorescent agent. When it encounters ultraviolet light (sunlight, fluorescent lamp, mercury lamp are more), it will produce fluorescent effect and emit white light, which makes the color look dazzling fluorescent. The fluorescence principle of fluorescent pen is different from that of our watch and fluorescent rod. The fluorescent rod is a radioactive reaction that occurs inside, and the radiation generated excites the phosphor around, so they can emit light at night without any ultraviolet rays. The fluorescent pen will fluoresce only when there is ultraviolet light. You can see this very clearly as long as you put the handwriting of the fluorescent pen close to the mosquito trap and the money detector.

The fluorescent pen has fluorescent agent. When it encounters ultraviolet light (sunlight, fluorescent lamp, mercury lamp are more), it will produce fluorescent effect and emit white light, which makes the color look dazzling fluorescent. Now there are also colorless fluorescent pens that can be hidden. There is no color after writing, and the written content can be displayed after being illuminated by the purple light behind the pen.

The fluorescent pen has fluorescent agent. When it encounters ultraviolet light (sunlight, fluorescent lamp, mercury lamp are more), it will produce fluorescent effect and emit white light, which makes the color look dazzling fluorescent. Now there are also colorless fluorescent pens that can be hidden. There is no color after writing, and the written content can be displayed after being illuminated by the purple light behind the pen.