Whenever I sent documents to one south american client, he only request me to sign on it, I asked why no stamp, he told me "it's not Chinese custom who only admit stamp"...

So I am surprise, how about other coutries?

Replying to [heshelleyatgmaildotcom]: What do you mean by stamp? Are these the chinese character name of the person? If yes, I think it is the customs of Chinese and other countries do no5t do it. The signature would be enough. Some in Japan also have stamps but this are usually reserved for official documents and I think the status of the signatory. Even the companies I believe have their own stamp. Hope this help.

Replying to [heshelleyatgmaildotcom]:

Hi!

All this things is depending on country-to-country regulations.

To be correct not each country policy requests that the companies to have the stamp or seal and the USA is one of them.
It is quite enough for them that the documents (contract, invoices, etc) to bear only signature. If company has stamp/seal it's Ok, but if not it doesn't make docs only signed incorrect/non-authenticated.

As for my location, Ukraine, it is necessary that all ukrainian companies to have their stamp (duly registered and authorised by the local authorities of internal affairs).
But it is also clearly explained by the Ukrainian Ministry of Economy that the contracts between residents and non-residents of Ukraine should not obligatory have the stamp/seal of non-residents...Only the signature is enough and to be accepted by the authorities.

So there is no tricks or fake....

If they do not need Your docs to be sealed/stamped then let them have only signed.

Good luck