Canon LBP7100Cn User Manual page 146

[Paper Size]
[Paper Feed Direction]
[Paper Type]
For details on the basic printing procedure, see
If printing custom size paper, you need to register the custom paper size in the printer driver previously.
"Registering a Custom Paper Size"
Select the size of the paper loaded in the paper drawer.
When [Free] is specified, the paper size of the printed job is registered automatically
each time printing is completed.
Select the feed direction (orientation) of paper loaded in the paper drawer when using A5,
Statement, or custom size paper.
Select the type of the paper loaded in the paper drawer.
When [Free] is specified, printing is performed without checking the paper type.
When [Free] is specified, be sure to check that the paper type setting of the printer
driver matches the type of paper loaded in the paper drawer at the time of printing.
"Basic Printing Procedure."