You can use the printer driver to specify the paper type.
When specifying the paper type, you can use the printer or copy display to check which of the machine's trays contains which type of paper.
Note however that the paper sizes you can select with the printer driver might not match those displayed on the machine's printer or copy display. When specifying the paper type with the printer driver, make sure that paper of the type you are selecting is actually loaded in one of the trays.
You can specify the paper type on the [Tray Paper Settings] tab in [System Settings]. For information about “Paper Type”, see “System Settings”, General Settings Guide.