Because the signature has legal effect and must stand the test of time, it is required that the handwriting can be preserved for a long time and the handwriting will not be blurred. The previous rule was to sign with a brush, because ink can be preserved for a very long time, which can also be confirmed from some unearthed cultural relics. However, due to the great inconvenience of using a writing brush, when the pen appeared, it was changed to a pen because its handwriting could be preserved for a long time. Signature pen is a newly developed pen, which is adopted because its handwriting can be preserved for a long time and it is more convenient to write and carry than pen. At present, the signature pen is the same as the signature pen, which is just my personal preference.