I have been given specific specifications for creating PDF files for a client.
They are as follows:
PDF A/1 (e.g. pdf v. 1.4 with lossless compression).
PDF A/2 guidance (e.g. pdf v. 1.7 with high/loss compression such as JPEG2000).
What is the best way to create these formats? We are currently using Adobe Acrobat X and the files at the minute are just PDF's but and different versions.
In Acrobat X you can choose File > Save As > More Options > PDF/A then press Settings to choose the version and converter parameters.
However, in many cases this automated conversion to PDF/A will fail. It's advised to create PDF/A files directly from the original application rather than to create "generic" PDFs then try and make them comply after the fact.
For example changing to lossless compression is pointless if the original PDF used JPEG compression, as without going back to the original document the uncompressed object simply isn't there. Similarly with PDF/A1-a (which requires structure tags) - you can't save to PDF/A1-a without those tags, and adding them manually to an untagged PDF is a nightmarish task compared to a re-save of the original with the tags turned on.