Your scanned PDF has 3 cm of blank margin on every side. The footer with the scanner's date stamp is on every page. You want the actual content, nothing else.
Cropping trims the page size to show only what you want. The hidden content stays in the file but isn't visible.
Decide the crop area
Open the PDF and find the area you want kept. For removing margins, look at the smallest margin needed to keep the content safe (usually 5-10mm).
For removing a header or footer, identify exactly where they end. Crop just inside that line so no part of the stamp shows.
Apply the crop
Open the file in Flint's editor and use the crop tool. Drag the crop handles to the new boundaries. Apply to all pages for consistent cropping.
For pages with different content (a cover with a header you want kept, body pages without), apply different crops per page range.
Confirm and save
Check the cropped result at actual size. Make sure no content was trimmed by accident. If headers or text are clipped, undo and re-crop.
Save the file. The cropped version is smaller in physical page size and often smaller in file size too — Flint optimises the saved version.
FAQ
Will cropping remove content permanently?
The content stays in the file but isn't visible or printable. To remove it for real, use redaction.
Can I crop a single page differently?
Yes — apply different crops to different page ranges. Useful when a cover and body pages need different treatment.
Will the printed page match the cropped view?
Yes. Printers respect the cropped page size — what you see is what you print.
Can I undo a crop later?
If you keep the original, yes. The cropped file's hidden content is still there but accessing it requires un-cropping in the editor.
Cropping is a precision job. Open your PDF in Flint's editor, set the boundaries, apply.