When someone says "send it as a PDF," they usually mean a standard PDF. But for specific industries โ archiving, printing, engineering โ different PDF standards exist that go beyond what a regular PDF provides. Here is everything you need to know.
Standard PDF (PDF 1.x / PDF 2.0)
This is the everyday PDF most people use. The current standard is PDF 2.0 (ISO 32000-2:2017). It supports:
- Text, images, vector graphics
- Hyperlinks, bookmarks, annotations
- Embedded fonts
- Form fields and digital signatures
- Password protection and encryption
For most personal and business uses, standard PDF is all you need.
PDF/A โ Archival Standard
PDF/A (ISO 19005) is designed for long-term archiving. It guarantees a document will look exactly the same in 50 years as it does today. Used by:
- Government and legal archives
- Libraries and educational institutions
- Healthcare records
Key restrictions: No encryption, no embedded audio/video, no JavaScript. All fonts must be embedded. Colours must be fully specified.
PDF/A has three conformance levels: PDF/A-1 (strictest), PDF/A-2 (adds transparency and JPEG 2000), and PDF/A-3 (allows embedding of any file type inside the PDF).
PDF/X โ Print Production Standard
PDF/X (ISO 15930) is designed for professional print exchange โ print-ready files sent to commercial printers, newspapers and publishing houses. Key requirements:
- All fonts must be embedded
- Colours must be CMYK or specified spot colours (not RGB)
- No transparency in PDF/X-1a (the most common sub-standard)
- Trim box and bleed box must be defined
If a printer asks for "a PDF/X-1a file," they want print-ready files that will reproduce colours and layout precisely on a commercial press.
PDF/E โ Engineering Standard
PDF/E (ISO 24517) is designed for engineering and technical documents. It adds support for 3D content, interactive animations and rich media relevant to CAD and engineering workflows. Less commonly encountered in general use.
PDF/UA โ Universal Accessibility
PDF/UA (ISO 14289) ensures PDFs are accessible to people with disabilities โ screen reader compatible, properly tagged, keyboard-navigable. Required for government and public-sector documents in many countries.
Which Standard Do You Need?
- Everyday document, email, sharing โ Standard PDF
- Legal, government, medical records โ PDF/A-1b or PDF/A-2b
- Sending files to a commercial printer โ PDF/X-1a or PDF/X-4
- Public sector / accessibility required โ PDF/UA
- Engineering / CAD documentation โ PDF/E
๐ When in doubt, use standard PDF. Only switch to a specific standard when the receiving organisation or system requires it.