I have a document that recipients are expected (or are likely) to print on their own. It is not clear whether the majority of users will be US or non-US, so there isn't a clear preference for letter or A4 paper.
Assuming that I can't know how many recipients will want letter and how many will expect A4, what would be the more appropriate page size to use for a PDF?
To put it another way: which will cause less issues for users:
- printing a letter sized document using A4 paper
- printing an A4 sized document using letter paper