Related instructions

There are several kinds of organic dyes that usually make red ink: ink red, poinsettia and acid red G, which are very unstable. Therefore, glycerin, alcohol, formaldehyde, gum and antioxidants should be added to the red ink. Even so, red ink is still very unstable, and it is generally forbidden to file materials written in red ink in regular files.

When writing a note or letter, it means breaking up or giving a malicious warning.