Canon MG6600 Series Manual page 672

1310
Cause
The size of paper may not be compatible with automatic duplex printing.
Action
The sizes of media suitable for auto duplex printing are A4 and Letter. Make sure that the size of the
paper loaded in the machine is correct. Tapping OK on the touch screen will eject the paper and restart
printing from the front side of the next paper. The reverse side of the ejected sheet will not be printed.
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