Canon LBP7780CX User Manual page 151

In case of portrait orientation (only when the UFR II printer driver is used): Short edges 210.0 to 215.9 mm;
Long edges 210.0 to 215.9 mm
In case of landscape orientation: Short edges 148.0 to 215.9 mm; Long edges 210.0 to 355.6 mm
*16
You can load 164 to 176 g/m² heavy paper.
*17
Automatic 2-sided printing can be performed on the custom size paper whose short edges are 148.0 to 215.9 mm
and long edges are 210.0 to 297.0 mm.
*18
Automatic 2-sided printing can be performed on the custom size paper whose short edges are 148.0 to 215.9 mm
and long edges are 210.0 to 355.6 mm.
*19
The following Index Card size is supported.
76.2 x 127.0 mm
IMPORTANT
About print speed
The print speed may drop depending on the paper settings for the size, type, orientation, and number of copies.
Precautions for paper
"Precautions for Paper"
NOTE
Printable area
"Printable Area"
Envelope sizes
The envelope sizes are as follows.
Envelope Monarch
Envelope No.10
Envelope DL
Envelope ISO-C5
Chlorine-free paper
Chlorine-free paper can be used with this printer.
98.4 mm x 190.5 mm
104.7 mm x 241.3 mm
110.0 mm x 220.0 mm
162.0 mm x 229.0 mm