Posts tagged "pdf"

Drawing a black rectangle over text in a PDF does not redact it. We show how proper redaction strips the underlying content stream, why metadata matters, and famous cases where it went wrong.

Why do some PDF forms work everywhere and others demand Adobe Reader? It comes down to two competing PDF form standards. Here is what each does and why one is dying.

From the TSA 2014 manual to the Manafort 2019 filing, the most famous PDF redaction failures all happened the same way — a black rectangle drawn in a generic editor over text that was never actually removed. Here are the specific mistakes and how to verify before you ship.

A PDF exported from PowerPoint can be 50MB. The same content as a compressed PDF can be under 5MB. Here is exactly what gets compressed and how the algorithms work.

Most PDFs are accessibility nightmares — untagged content, no reading order, images without alt text. Making a PDF accessible is not difficult once you understand what a tagged PDF actually is.

A PDF digital signature is not a scanned image of your handwriting — it is a cryptographic proof tied to a certificate. Here is what it actually verifies and what it does not.

PDF and DOCX both contain text and images, but they are designed for fundamentally different purposes. Choosing the wrong format causes friction for everyone who receives the file.

A PDF looks like a printed page but is actually a complex container format with embedded fonts, compressed image streams, and a cross-reference table. Here is what is actually inside.