Highlighters are often used for drawing and marking. When selecting, you can fold two pieces of translucent report paper or typing paper together, write a few words on the top paper with a fluorescent pen, pay attention to the weight and cadence, and then turn it over to check. The high-quality fluorescent pen should have no color penetration on the back of the top paper, and there should be no handwriting on the next paper.

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.