This is Photosensitive Ink from XINWEI. 

It can change color rapidly under ultraviolet light.

The color-change effect brought by the Photosensitive Ink can be made reversible or irreversible.

The changed color can be adjusted according to customers' requirements.

The Photosensitive Ink of XINWEI can also play an anti-counterfeiting role and endow brand products with more fun and unique attributes.