Wet Signature

A wet signature is the classic way of signing: you put pen to paper and leave a mark in physical ink. The name comes from the ink being literally wet when you sign, before it dries. For centuries this was the only way to show you agreed to something, whether it was a lease, a sales contract, or a birthday card. The signature is your personal mark, and the physical paper it sits on is the record everyone keeps.

The catch with wet signatures is that they are slow and fragile. You have to be in the same room as the paper, or print it, sign it, scan it, and mail or email it back. The paper can be lost, damaged, or quietly altered, and proving who actually signed often comes down to comparing handwriting. None of that scales well when the people signing are in different cities or countries.

This is why electronic signatures exist, and why the law treats them as equal for most documents. In the United States, the federal ESIGN Act of 2000 and the model UETA of 1999 (adopted by 49 states plus the District of Columbia; New York instead relies on its own Electronic Signatures and Records Act, or ESRA) provide that a signature, contract, or record cannot be denied legal effect just because it is in electronic form. In the European Union, eIDAS (Regulation (EU) No 910/2014) does the same across member states. A signed PDF with a clear record of who signed and when can be just as enforceable as ink on paper, and often easier to prove.

A few document types still expect a traditional wet signature or extra formalities, such as some wills, certain family-law papers, and specific property or notarized deeds, and the exact list varies by country and state. For the contracts, agreements, and forms people sign every day, though, a tamper-evident electronic signature backed by an audit trail does the job a wet signature used to do, without the printer, the scanner, or the trip to the post office.

Examples

• Signing a paper lease at the leasing office with a pen and handing the physical copy back is a wet signature.
• Printing a contract, signing it in ink, then scanning it to email back still relies on a wet signature, just digitized after the fact.
• A notarized property deed is a common case where a wet signature and extra formalities may still be required.
• Signing the same lease as a tamper-evident PDF on your phone replaces the wet signature with a legally equivalent electronic one.