|PDF::Builder::Resource::PaperSizes(3)||User Contributed Perl Documentation||PDF::Builder::Resource::PaperSizes(3)|
The PDF specification (and PDF readers) default to US Letter size (portrait orientation, 8.5 inches wide by 11 inches high). If you want to use anything else, you will have to make a "mediabox()" call to specify the media (paper) size. For named sizes, capitalization doesn't matter (all entries are folded to lower case, so 'A4' and 'a4' work the same).
Different sources give somewhat different paper dimensions, especially for archaic or unusual sizes, so take care and measure your actual paper before printing, so you can avoid wasting paper and time printing to the wrong mediabox! Also keep in mind that many printers cannot print all the way to the edge (don't want to get ink or toner on the paper rollers), so set your margins accordingly.