Document.PrintPagesAcross Property (Visio)
Indicates the number of sheets of paper on which a drawing is printed horizontally. Read/write.
You must set the value of the PrintFitOnPages property to True in order to use the PrintPagesAcross property. If the value of the PrintFitOnPages property is False, Microsoft Visio ignores the PrintPagesAcross property.
The PrintPagesAcross property corresponds to the Fit to sheet(s) across setting in the Page Setup dialog box (on the Design tab, click the arrow in the Page Setup group).