Creating valid PDF/A-4 with CapyPDF

PDF/A is a specific version of PDF designed for long term archival of electronic data. The idea being that PDF/A files are both self contained and fully specified, so they can be opened in the future without any loss of fidelity. Implementing PDF/A export is complicated by the fact that the specification is an ISO standard, which is not publicly available. Fortunately, there are PDF/A validators…