How does Ziguang check stamps?

According to the anti-counterfeiting position of stamps.

Fluorescent encryption anti-counterfeiting ink

Stamp is a valuable ticket with its seriousness and artistic value. It is different from the logo of other products. Although the picture of a stamp is small, it is rich in content, level and color. Stamp printing itself is a combination of art and superb printing technology. On the premise of not destroying the artistic effect of stamp images, it is indeed difficult to implement anti-counterfeiting technology that can be recognized by the public on stamps. Using fluorescent encryption anti-counterfeiting ink is undoubtedly the first choice, which can give consideration to art and anti-counterfeiting. Through the use of stamps in recent years, they are very popular among stamp collectors. This kind of ink is different from ordinary fluorescent ink and has double anti-counterfeiting performance. It is the only anti-counterfeiting ink used in stamp printing. For example, the "27th Olympic Games" sheetlet printed with fluorescent encrypted anti-counterfeiting ink in 2000, under the excitation of violet light, can clearly see the yellow fluorescence of the yellow ring in the five rings, which can not only be used for public identification, but also have the arbitration function, and can further show the authenticity by using special instruments. By consulting domestic and foreign materials, the same anti-counterfeiting technology as this fluorescent anti-counterfeiting ink has not been found. At present, the Stamp Printing Bureau has developed five varieties, which can be combined in many ways to distinguish different products.