Canon BJC-S820D User Manual page 186

Printing Area
To ensure that the best print quality, the printer allows a margin along each edge
of media.
Printing area (dark blue): Canon recommends that you print within this area.
Printable area (light blue): The area where it is possible to print. However, printing
( )
in this area can adversely affect the print quality or the
paper feed precision. (
4" x 6", A4, B5, A5
Letter, Legal
Envelopes
Banner Paper
Specifications
)
186