Why re-creating the page is the wrong move
The obvious approach is to print the signature page, scan the signed version, and rebuild the document around it. Every step in that chain changes the page. A scan resamples it, a rebuild re-encodes it, and the result no longer matches the copy the other side holds.
Copying an existing page into a new document does none of that. The page object moves across intact, with the same content, the same resolution and the same embedded signature image. If someone later compares the appended page against the original file, they match.
The order people get wrong
A signed page belongs at the end of the body it signs, not at the front of the file. Assembled the other way round, the signature appears to cover a document the signer never saw.
Dragging rows is the whole mechanism. Put the body first, the signature sheet last, and any annex after that if it was referred to in the body.
- Cover sheet first, if there’s one and it’s unsigned.
- The contract body, in its original page order.
- The annex or schedule, if the body refers to one.
- The signed page last, because it’s the page that attests to everything above it.
The signature is an image, and a page copy preserves it exactly
A drawn or pasted signature in a PDF is a picture embedded in the page, either a bitmap or a vector group. Copying the page copies that object with it, at whatever resolution it was embedded at. Nothing re-renders it and nothing re-compresses it.
This is why the merge tool is the right instrument for this and a screenshot isn’t. A screenshot of a signed page is a new, resampled image of a signature; the page itself is the original.
If a page carries a digital signature, don’t append to that file
A certificate-based signature records a hash of the document as it stood when it was signed. Appending a page changes the file, so the signature is invalidated. The reader will report the document as modified, and it will be right.
The way round it is to keep the signed document whole and put the addition in a separate file, or to use the signature field the signer’s tool provided for exactly this purpose. Neither is something a merge can do for you, and a tool that claims otherwise is describing a different operation.
Strip what should not travel
Before the combined file goes out, look at what came with it. The metadata tool shows the title, author, producing software and timestamps on the merged document, but note that merge already discards the source metadata, so what’s left is whatever the new file was written with.
If the contract body carries an identifier on every page that shouldn’t be in the annex, redact is the tool for that, and it has to run before the merge rather than after.