Things may change slowly in the PDF standards world… but they do change.
The original PDF/A-1 standard, published in 2005, was developed to insure that digital documents that are archived for possible future use can be accessed when needed. PDF/A-1 is based on a version that existed before PDF was published as an open standard by the International Organization for Standardization (ISO) in 2008.
PDF/A-2 is based on the open standard, allowing it take advantage of new PDF features that make documents more usable while still being appropriate for long term archiving. Those new features include:
- Transparency - Transparent objects are now allowed in PDF/A-2. Transparency can be used to improve the appearance of PDF documents or to highlight content
- JPEG 2000 Image Compression – JPEG2000 offers server advantages such as both lossless and lossy compression for high quality and improved compression performance. This format was not available until after PDF/A-1 was published.
- OpenType Fonts - OpenType fonts can now be embedded without having to convert them into PostScript Type 1 or TrueType.
- Layers – Layers, also known as “optional content” in PDF syntax are now allowed in PDF/A-2. Layers are essential for selectively viewing different aspects of complex CAD files. They are also used for including multiple languages in the same PDF file, allowing users to display.
- Enhanced Annotation Support – PDF/A-2 supports several new annotation types. Comments and mark-ups added to PDF files using supported annotations can now be included in archived files.
Don’t Worry, your Archives are Still Valid!
Existing PDF/A-1 files will continue to be valid under the new standard. Running them through a PDF/A conversion that is PDF/A-2 compliant won’t change anything because any features allowed under the PDF/A-2 specification would have already been removed to make them valid PDF/A-1 files.
Now that the ISO PDF standards committee has ratified the new standard, it goes to the ISO organization for final publishing. We at Adlib are currently reviewing the new PDF/A-2 standard for incorporation in a future release of our software.