I have a some very valuable website content that I have archived by printing to PDF using Adobe Acrobat Professional. What follows is true for websites but also any other sort of file you want to preserve.
The take-away from the post is that if you want to preserve digital content and be able to re-purpose it in future then you must set your PDF printer to use PDF/A. Unsurprisingly the /A stands for “Archive”.
The following pictures shows what can happen.
The original web page
The PDF Images
There is no visible difference between PDF/A and PDF standard.