To set up paper size, use
PrintOptions.PaperSize[
^] property of Crystal Report. You should be warned that there is a
paper size enumeration[
^]. It means that you can't set any custom paper size, but the one from collection. If you would like to set up default paper size for printer, please see:
Adding custom paper sizes to named printers[
^].
Alternativelly, you can print data using
PrintDocument[
^] class (designed for printing from a Windows Forms application).