Cropping is not redaction. Here’s the difference.
Understand what actually removes sensitive information before you share a PDF.
Cropping changes what is visible
A PDF crop box tells a viewer which part of a page to display. Content outside that area can remain in the file and may be recovered by changing the crop box or extracting text. Cropping is useful for margins, but it is not a safe way to conceal confidential information.
A black rectangle is not always redaction
Drawing a black shape over text may leave the original text underneath. A recipient might still copy the text, extract it, or remove the overlay. Use a workflow that removes the underlying source material in the exported file.
How PaperLumo redaction works
PaperLumo renders each page, paints the chosen rectangle into the resulting image and builds a new PDF from those images. It does not copy the original text layer, links, attachments or document metadata into the new output. The same selected rectangle is applied to the page numbers you choose. Coordinates are percentages measured from the top-left of the visible page.
Always verify what you are sending
Inspect every redacted page and confirm that the entire sensitive area is covered. Check other pages for repeated information and check the filename itself. The output is image-only, so accessibility and selectable text are lost. The first-page preview cannot verify your entire document for you.