You signed off the year-end report on Tuesday. By Friday, someone's reopened it, added a comment in the margin, and re-saved it. The version that went to the board now exists in two states.
Flattening is the prevention. Do it before distribution.
What flattening does
Flattening converts annotations, signatures, form fields, and comments into static page content. Once flattened, they can't be moved, edited, or removed. The PDF still displays exactly the same — but the layers are gone. Use Flint's flatten flow after signing, annotating, or commenting and before distribution.
When to flatten
After all annotations are final. After all signatures are captured. After the final review comments are addressed. Never before — flattening is one-way, and re-adding annotations to a flattened PDF is harder than editing live ones. The rule: flatten at the very last step before distribution.
What flattening doesn't do
It doesn't remove metadata — author tags, creation date, document properties remain. For financial reports going outside the firm, also clear metadata. Flattening also doesn't password-protect; combine with password protect for fully locked distribution.
Practical workflow
Annotate or sign in annotate PDF or sign PDF. Review with the team. Once approved, flatten. Then password-protect. Then send. Four steps in order — never skip flattening, and never flatten before approvals are final.
FAQ
Can a flattened PDF be unflattened?
Not in practice — flattening is one-way for all standard tools. Some forensic recovery is theoretically possible but well beyond ordinary use.
Do I lose interactive form fields when flattening?
Yes — fields become static text. If you need the form to remain fillable, don't flatten.
Does flattening change file size?
Usually slightly larger because annotations become embedded rendering. The difference is negligible.
Should I flatten before or after signing?
After — flatten captures the signature visually but doesn't lock the signature's cryptographic properties.
Flatten before distribution. Annotate, flatten, and lock in Flint and your reports stay as they were when you signed them off.