What is Flattening a PDF?

What does Flattening a PDF mean for your PDF?

Live objects sit above the page: a form field holds a value, a sticky note holds a comment, a drawn signature is an annotation. Anyone who opens the file can change or delete them, and some readers never save field values at all.

Flattening paints their appearance into the page content and deletes the live versions. The document becomes what a printout is: fixed.

It does not hide anything. A flattened page with an account number on it still shows the account number — permanently. Removing text is a different operation.

When is flattening the right thing to do?

Before a filled form leaves your hands. The values you typed live outside the page until they are flattened, which is why a recipient can open your completed application and see empty boxes, or change a figure without leaving a trace.

It is also the fix for a document that prints wrong. Readers that ignore field appearances print the blank template; a flattened file has nothing left to ignore.

And it is the honest way to finish a signed document: a drawn signature that is still an annotation can be dragged off the page and dropped onto another one.

• Flatten: filled forms you are submitting, signed agreements, documents with stamps or approval marks.
• Do not flatten: a blank template others still need to fill in, or a draft you will keep editing.
• Flatten last: once it is done, the fields are gone and the only way back is your earlier copy.