Here we show example with half page normal size: 8.5 x 5.5 inches.
Go to Start/Settings/Printers and select the printer. With Right mouse select properties (or printing preferences) and find printer selection size. Locate a custom setting choice and specify 8.5 for width and 5.5 for height and save that with either giving it a "8.5 x 5.5" name or "Custom" something choice name available.
Go to Start/Settings/Printers and select the printer. In the box file menu
select "Server Properties".
In the Forms tab check [x] create a new form and fill in entries in the lower part as shown (the example is for 8.5x5.5 size sheet). The name given is "8.5 x 5.5"
Click on [Save Form] button and exit.