What do haunted houses and gift shops have in common during Halloween? From scary masks to dream-filled stars, these glowing things in the dark bring different visual sensations to walls and ceilings. But why are these objects glowing yellow-green?

Although many colors can be used to make phosphorescent or luminous products, yellow-green is by far the most popular and brightest color. Part of the reason lies in the inherent characteristics of color: for some reason, the yellow-green objects found in haunted houses are more creepy than blue and yellow. (This property of yellow-green also applies to other toys, such as train tracks, Rubik’s cube)

However, a more scientific reason is that green is a popular color, because most luminous products absorb energy (in this case, light), and then slowly release energy because light and light have the same chemical elements: Zinc sulfide. This chemical is usually mixed with other chemicals to make it more stable and can be used in paints, plastics, and other applications.

Zinc sulfide is non-toxic, relatively inexpensive to produce (thus making it very suitable for cheap toys), and can naturally emit this unique green color. Noctilucent powder containing zinc sulfide is called short-acting noctilucent powder, which has fast light absorption and short afterglow time. Although it is non-toxic, it will release toxic gases during the production process, so it is difficult to see this short on the market now—effective luminous powder.

Rare earth luminous powder, also known as long-acting luminous powder, compared with short-acting luminous powder, the light absorption speed is slow, the afterglow time is long, non-toxic, non-polluting, and no radioactive substances, so short-acting luminous powder is slowly being long-acting luminous powder Replaced by. The two luminous powders have different advantages. In choosing, you should choose the product that suits you.