Whether it is a red seal or a blue seal, it is the same when signing an agreement or contract, and it has legal effect.
1. Influenced by traditional culture, enterprises and institutions in our country generally use red ink ink, and rarely use blue ink ink. However, it is mostly used by foreign trade enterprises or foreign capital. They usually have square seals and need to be covered with blue ink.
2. In ancient Chinese calligraphy, blue ink paste is generally used during mourning, so blue is not used when signing formal legal documents.