Writing a letter with a red pen is a sign of breaking up friendship. In ancient times, a red pen was used to record the names of criminals. Until now, criminals’ names are marked with a check mark or a cross with a red pen. People are taboo to use red pen to write letters. It is common to use ballpoint pens and fountain pens. Younger letter writers will use pencils, and some older people who like calligraphy will use brushes.
Font color:
Generally, black is the main color and blue is preferred. Red must not be used. Using red is disrespectful to the recipient and also expresses the intention to break up the relationship. You should also not use brighter colors, which may irritate other people's eyes, make it difficult to read, and appear not solemn enough.
When choosing letter paper, you can choose letter paper with rich shading according to the content of the letter. Firstly, it can increase the mood and interest in reading; secondly, it can appropriately adjust the visual effects of the other party to avoid a monotonous and rigid feeling.