You receive a signed contract. You drag the signature with your mouse — and it moves. The signed amount field is editable. You realise the document you've been treating as final is fully editable by anyone who opens it.
Unflattened PDFs are a real problem. Flattening fixes it.
What flattening does
A PDF can have multiple layers — text content, annotations, signatures, form fields, embedded comments. Each layer is editable independently in many PDF tools. Flattening merges all layers into a single visual surface — pixels, not editable layers.
After flattening, the signature is part of the page; nobody can drag it. Annotations are baked in. The PDF behaves as a final visual artefact.
Why it matters for signatures
An unflattened signature is essentially a sticker placed on the page. The recipient can drag it elsewhere, delete it, or copy it onto a different document. None of that is what you intended when you signed.
Flint flattens signatures automatically on download. Verify by opening the signed PDF and trying to move the signature — if it moves, it's not flattened.
Why it matters for annotations
Sticky notes, highlights, freehand marks — all editable in unflattened PDFs. Recipients can delete or modify your annotations without trace. For draft review, this is often desired. For final delivery, it's not.
Annotate in Flint, then flatten before sending. Your marks become permanent visual artefacts on the page.
Why it matters for form fields
PDFs with form fields can be modified by anyone who opens them — fields filled, cleared, or changed. If you're sending a filled-in form as a record, flattening locks the data into the visual page.
This matters for compliance and audit. A flattened filled form is evidence; an unflattened one is an editable template.
FAQ
Are there reasons not to flatten?
For drafts under iteration, no — you want to preserve annotations and form fields editable. For finals, always flatten.
How do I check if a PDF is flattened?
Open in a PDF reader, try to select or drag overlay elements (signatures, annotations). If nothing moves or selects, it's flattened. If you can drag the signature, it's not.
Does flattening reduce file size?
Sometimes — by collapsing multiple layers into one. Combine with compression for the smallest output.
Can I re-edit a flattened PDF?
Limited. You can add new layers (new annotations, new signatures) on top, but the flattened content underneath is pixel-locked. For edits, go back to the source.
Flattening is the small step between 'shared draft' and 'final artefact'. Sign, annotate and flatten in Flint — every outbound PDF should be locked.