paperType

Set the PostScript paper type.
[write-only property] paperType([in] BSTR size)
This property sets the paper size for PostScript output. The available options are "letter" (the default), "legal", "A4", "A3", and "match".

PDF pages which are larger than the specified paper type will be scaled down to fit.

The last option, "match", is a special setting which instructs XpdfPS to set the paper size to match whatever is specified in the PDF file.

Setting the paperType property is a shortcut to calling setPaperSize with the corresponding width and height. setPaperSize can be used to set an arbitrary paper size.

This setting is global, i.e., it affects all XpdfPS objects (in the same process).

VB6:
pdf.paperType = "A4"
setPaperSize