The working principle of a tattoo pen is relatively simple and clever. The pen tip contains a special formula of ink, which can quickly dry and adhere to the epidermal layer when in contact with the skin, forming a semi permanent color film. This film has good waterproof and sweat resistant properties, and can maintain the clarity and brightness of the pattern for a period of time. Meanwhile, with the natural metabolism of the skin, tattoos will gradually fade until they disappear completely, without any special care or removal methods required.