Starting From the Top
The PDF (which, by the way, stands for Portable Document Format) is pretty ubiquitous in computing culture, and really shouldn’t need an introduction. But after continuous, everyday file-transfer and internet use, its obvious benefits blur into the background. Let’s take a step back and remind ourselves why the PDF format rocks.
As detailed in sustainability documents from the Library of Congress, the PDF format family was developed by Adobe, which made the specifications open and available at no charge. To promote their use, Adobe licensed a bunch of patents on software that produce, consume, and interpret PDFs on a royalty-free, non-exclusive basis. In 2008, when PDF version 1.7 was adopted as ISO standard 32000-1:2008), Adobe issued a Public Patent License granting "every individual and organization in the world the royalty-free right [...] to make, have made, use, sell, import and distribute" the implementation of the PDF.
Why does this matter? Well, after Adobe essentially gave up ownership claims on the format, it became supremely-widely adopted as the way to distribute paged documents, with software to read the format bundled with (pretty much) every PC. This is what we mean when we say “ubiquitous”, and in terms of digital preservation, ubiquity is huge. As we wrote last week, your digital work lives and dies by A) the technology that is reads it, and B) how many other people in the world use that technology. This makes PDFs a massively safe bet for the future readability and compatibility of your label's documents.
When and Why?
There are clear advantages to using PDF files to store your documents, just as there are clear advantages to using word processing programs (such as Microsoft Word or OpenOffice). An oldie-but-goodie post over at at PlanetPDF recommends a common sense approach: word processors for editing, PDFs for the final product. Retaining a PDF of your final draft eliminates any potential cross-platform formatting problems associated with exchange between users or printing. Furthermore, printing PDFs from a word processing program ensures that your text can be copied and pasted in the future.
PDFs and Archiving
In 2002, a little over 10 years after the format was introduced, Adobe was already touting the PDF as a standard for archiving. After a testing and approval phase, the ISO published ISO 19005-1:2005, or PDF/A, the first standardized file format for long-term digital archiving ensuring that documents can be reproduced perfectly for the foreseeable future.
So what’s the difference between PDF and PDF/A? According to PDFAssociation, a PDF/A file is just a normal PDF that forbids certain functions which could prevent perfect reproducibility. The key differences are:
- PDF/As must not be encrypted
- PDF/A avoids any material that requires external software for display or playback (so embedded audio and video are out)
- All used fonts must be embedded within the PDF, and
- Use of standards-based metadata is required (yay!)
So how do you make a PDF/A file? It’s a simple process that can be done when you export a document from a word processor. When saving to PDF in Microsoft Word, click on the “Options” button:
One final thought: beware web sites that say they will do the conversion for you. You don’t want someone else saving a copy of your label’s stuff.