PicoPDF's Edit/Redact function covers sensitive information with black boxes, but clicking on them afterward can reveal the content because the redaction may not be fully permanent until properly applied. This is a common issue in PDF editors where the blackout acts like an overlay rather than deleting the underlying data.
Proper Redaction Steps
Select the Redact tool under the Edit tab, drag over sensitive areas to mark them, then click "Done" to apply changes permanently. Save the file as a new PDF afterward to ensure the original data is not recoverable, and test by searching or copying text from the blacked-out sections.
Troubleshooting the Issue
Avoid clicking or selecting the blacked-out areas post-redaction, as this can toggle the overlay in some editors like PicoPDF. If the problem persists, flatten the PDF layers (via Print to PDF) or use "Apply Redactions" explicitly if available, preventing easy removal of the blackout.
Verification Tips
Open the saved file in another PDF viewer and attempt to select, copy, or search the redacted text—if it fails, the redaction succeeded. For critical documents, combine with metadata removal to eliminate hidden info.