Optimal file sizes for access PDFs

Question

We have digitised a collection of old books, pamphlets, etc, which we will be making available as PDFs and as images through BookReader. The original files were scanned as TIFFs and will not be available to users. The PDFs we originally created were high quality and large file sizes; some over 100  MB. Obviously, this is far too large to expect most users - which will be the public - to download. Is it better to split the larger files into smaller and retain the high quality? Or regenerate the PDFs into smaller, lower quality files? And in either case, what is the ideal maximum file size for cultural heritage-type PDFs available to the general public? Have not been able to find any recommended standards at all around this issue.

Answer 1

No answer from anyone, so I guess my comments about there being no recommended standards is confirmed!

What we choose to do was:

* Make the large, high quality PDF, available from our repository (which has primarily an academic audience)

* Make a smaller, lower quality PDF, available from our exhibition software (which is focused at both academics and the general public), with a link to the high quality PDF in the repository

Initially, we were thinking of a 20MB file size limitation on PDFs in our exhibition software; but ended up increasing that to around 40-50MB. Our rationale there was that because we had embedded the BookReader software, and the BookReader software downloads on a page-by-page basis, users would be able to check items in the BookReader before choosing to download the PDF. So if users did choose to download the PDF, it would be because they knew it was what they wanted, and thus they'd be prepared to put up with a larger download.