Thirty two years ago, Adobe launched Acrobat and the Portable Document Format. Two years later, in 1995, I met Duff Johnson. He walked into my office, and I showed him what we were doing with PDF. The rest, as they say, is history.

That same year, my company Emerge was named Adobe’s Premium VAR (Value Added Reseller) of the Year, a recognition that reflected just how quickly PDF was starting to reshape the world of documents and digital workflows. We were all learning in real time what “digital paper” could become and nobody could have guessed how far it would go.

Since then, Duff has been one of the leading forces behind PDF’s evolution first as an evangelist, later as the architect of its standards, and now as CEO of the PDF Association, the global body that maintains the format’s technical and accessibility specifications.

When Adobe released the PDF specification to ISO in 2008, Duff and a small international team took on the responsibility of ensuring the format’s long-term health. Today, PDF is second only to HTML as the most common format on the web—used everywhere from contracts and invoices to shipping labels and government archives.

“PDF has become nearly invisible infrastructure,” Duff said. “Everybody assumes it’s there and that it just works. Try living without it.”

The Shape of Digital Paper

Most people think of PDF as “digital paper” or a way to fix the look of a page on screen. But Duff reminds us that under the hood, PDF is a page description language capable of carrying structured data, annotations, forms, and even 3-D models. One developer once described it as a “free-form database,” and Duff agrees.

That flexibility is what has kept PDF relevant while other formats have come and gone. It allows developers to render exact replicas of printed output—or to extract, tag, and reuse data for accessibility, AI ingestion, or interactive applications. Half of all new PDF files created today are “tagged,” meaning they include semantic information that makes them readable by both humans and machines.

The Accessibility Imperative

Duff’s team has spent decades advancing tagged PDF and the global PDF/UA (Universal Accessibility) standard. Europe now mandates accessible PDFs for public content, and the U.S. isn’t far behind.

“Accessible PDF is far more in reach today than it’s ever been,” Duff noted. “The limitation isn’t technology. It’s policy, process, and training.”

AI will soon help here, too. Machine learning can propose headings, detect structure, or auto-tag content before a human validates it. The goal: billions of legacy PDFs made fully accessible without manual remediation.

PDF vs. Toilet Paper

During our conversation, I mentioned that critics have called PDF “the single-ply toilet paper of business documents” which is technically functional, but clunky, static, and frustrating on mobile. Duff laughed and didn’t disagree entirely.

“It’s actually one of my favorite analogies,” he said. “PDF and toilet paper have a lot in common. For example, nobody likes to talk about them, everyone assumes they just work, and you only notice when they don’t. But most importantly, try living without either one.”

In other words: the world might complain about PDF, but it can’t function without it. Reliable, secure, and universally shareable digital documents are as fundamental to modern life as running water or, toilet paper.

TreelinePress is a reader-supported publication. To receive new posts and support my work, consider becoming a free or paid subscriber.

AI and the Future of PDF

If AI is the new frontier, PDF is one of its richest terrains. But, as Duff cautions, most AI systems treat PDFs like flat images by scraping text rather than reading the structured data they already contain. That wastes compute power and loses meaning.

He envisions a future where AI tools respect PDF’s internal semantics, reducing cost, improving accuracy, and allowing creators to embed “do not ingest” metadata for copyright control (the new TDMRep protocol).

“We’re waiting for the AI world to realize PDF isn’t just a picture. It’s data, structure, and meaning already packaged together,” said Duff.

What’s Next for the Standard

Current work at the PDF Association and ISO includes better compression, high-dynamic-range (HDR) imaging, and richer embedded content. These efforts ensure PDF remains future-proof for archiving, accessibility, and intelligent automation.

“PDF isn’t about nostalgia for print,” Duff explained. “It’s about reliability, authenticity, and the ability to share information offline and across systems. Try running a business or a civilization without that.”

Andy’s Take

For all the jokes about digital toilet paper, PDF’s real magic is in what it quietly enables: trust. It bridges decades of digital transformation without breaking a link.

It’s a file format that connects 1993 to 2025 an unglamorous but indispensable connective tissue spanning 32 years of our digital world.

PDF isn’t going anywhere. It’s just getting smarter.

Get full access to TreelinePress at treelinepress.substack.com/subscribe