If you need your report to show on a custom paper size not supported by the printer, you can use the ActiveReports virtual print driver. The following code in the ReportStart event, or just before .Run is called, will allow you to do so, and to use any paper size:
.Document.Printer.PrinterName = ""
Me.PageSettings.PaperKind = Drawing.Printing.PaperKind.CustomMe.PageSettings.PaperHeight = 2'sets the height to two inchesMe.PageSettings.PaperWidth = 4'sets the width to four inches