Black pen/ink

[MGM]

Always wondered. Why is it that only black ink is used on official documentation?

[Justloadit]

When the documents are photocopied, it ensures that a good replication of the signature.

The other problem with blank ink, with the quality of the copiers today, it becomes difficult to tell between an original and a copy. Depending on the documentation, some companies prefer you to sign in blue, so that you can tell the difference between an original and a copy.

[Phil Cooper]

Black ink - apparently - does not fade in time, whereas the other colours do.

[Hermes14]

When the documents are photocopied, it ensures that a good replication of the signature.

The other problem with blank ink, with the quality of the copiers today, it becomes difficult to tell between an original and a copy. Depending on the documentation, some companies prefer you to sign in blue, so that you can tell the difference between an original and a copy.

If you are not to sure if it is an original signature or a photo copy fell the back of the page.
A photo copy doesn't leave an indentation on the paper.

[Dave S]

If you are not to sure if it is an original signature or a photo copy fell the back of the page.
A photo copy doesn't leave an indentation on the paper.

But a fountain pen does not leave an indentation on the page anyway. There you go forgers, use fountain pens instead...

[Hermes14]

But a fountain pen does not leave an indentation on the page anyway. There you go forgers, use fountain pens instead...

Look at the way a fountain pen works.
Although the amount of pressure that you have to apply is miniscule, you still have to apply pressure on the paper for the ink of a fountain to flow.
You will get professional forgers out there & you may need a professional graphologist or a private investigator with a trained eye to determine if it is a forgery.