PDF/A is the archival profile of PDF. It exists because regular PDFs can quietly include things that might break in fifty years — external font references, JavaScript, optional dependencies.
Here is what PDF/A is, in plain language.
The short version
PDF/A guarantees the file opens identically in any future reader. To do so, it embeds everything (fonts, images) inside the file and forbids dynamic content.
The variants
PDF/A-1 is the strictest, based on PDF 1.4. PDF/A-2 adds JPEG2000 and transparency. PDF/A-3 lets you embed attachments. Most public archives accept PDF/A-1 or -2.
Who actually needs it
Government archives, court submissions in some jurisdictions, regulated industries with long retention (medical, legal, financial). Everyday business does not need it.
Tools that produce it
Acrobat Pro, LibreOffice (export option), some specialist scanning workflows. Flint focuses on daily editing. If you produce documents in Word, exporting via 'Save as PDF/A' is the easiest path.
FAQ
Is PDF/A bigger?
Slightly, because fonts and resources are embedded.
Can I edit PDF/A?
You can — but editing breaks the strict archival guarantee. Re-export to PDF/A after edits.
Will a regular PDF break in twenty years?
Probably not — PDF is very widely supported. PDF/A is the formal guarantee.
Day-to-day work: regular PDF in Flint. Decades-long archival: PDF/A via a tool that supports it.