Use fire paint
Use fire paint (aliad to seal wax, seal wax, fire paint wax, seal paint, seal wax, fire paint stamp, fire lacquer seal. It started to rise in about the 16th century. Used by nobles or rich people, it can also be used in the form of sealing parts of important documents or creating a sealed container seal. Mainly used for decoration, clinging books, decorative certificates and sealing envelopes, greeting cards and invitation letters. The previous role is mainly used to ensure that the content of envelope is safe.