Visible stamp or invisible signature: which should I choose?

In the Digital Signature tool, under "Where it goes", there is a tick box: "Show a signature stamp on the page". Untick it and the hint changes to *"The document is signed invisibly. Nothing is drawn, the signature is still there."*

That sentence surprises people, so let us take it slowly.

What the stamp actually is

When you leave the box ticked, a small box is drawn on the page showing some of:

• Name: "Digitally signed by ...", taken from your certificate,
• Date: when you signed,
• Reason: what you typed in the Reason box,
• Location: what you typed in the Location box,
• Labels: whether the words "Reason:" and "Location:" appear,
• optionally, a handwritten signature image you drew or uploaded.

You drag the box to where it belongs and drag its corner to resize it.

Here is the important part, and the tool says it too: the handwritten image is decoration. The certificate is what signs the document. A prettier stamp is not a stronger signature.

The everyday version

Think of a sealed envelope.

• The seal is the digital signature. It is what proves nobody opened the envelope.
• The stamp on the page is writing "Signed by Jane Doe, 3 March" on the outside of the envelope.

The writing helps people know what they are holding. The seal is what does the work. You can have the seal without the writing.

When to show a stamp

Most of the time. Choose visible when:

• a person will read the document and should see at a glance that it is signed,
• the document has a signature line where a signature is expected,
• you are sending it to someone who is not technical and would otherwise think you forgot,
• it is a contract, offer letter, invoice or anything with a conventional look people expect.

When invisible is better

Choose invisible when:

• the signature is for machines: a system that processes files and checks signatures automatically,
• the document's layout must not change at all, for example an official form or a certificate design,
• you are sealing an archive copy and nothing should be added to the page,
• there is simply nowhere sensible to put a box.

The protection is identical. Verification tools find an invisible signature exactly as easily as a visible one, in Verify PDF Signature it appears in the list like any other.

Signature fields: a third option

Some documents arrive already prepared with an empty signature field: a place the author set aside for a signature. When the tool finds one, it shows it on the page marked *Sign here*, and it is listed in the left panel.

Clicking it signs into that field, at exactly the size and place the author intended. That is usually the best choice when a field exists: the author planned for it.

Putting the stamp on more than one page

For a single document there is a tick box, "Repeat the stamp on every page", with the hint *"Still one signature: the same stamp is shown at the same place on each page."* Worth reading twice. Repeating the stamp does not create several signatures. There is one signature; the label is simply drawn in several places, as a court clerk might initial every page.

When you sign several documents in one batch, the same idea appears as a dropdown, "Stamp on": the last page of each document, the first page of each, or every page. The stamp keeps its distance from the nearest page edges, so it lands correctly on pages of different sizes.

A warning you might see

If your name uses characters the stamp's font cannot draw, you will see: *"Some characters could not be drawn in the visible stamp. The signature itself carries the full name from your certificate."*

The stamp is a picture with limits. The signature is not affected.

A completely different tool for a different job

If what you want is your own handwriting on a page and you have no certificate, that is Sign PDF, not this tool. It places a picture of your signature. The difference is set out in what is a digital signature in a PDF.