Canon BJ-200ex - Manual (Page 51)

3. Move the paper guide to the left to match the width of the
envelopes.
4. Extend the paper support and the paper output tray.
5. Prepare the envelopes.
§ Arrange the stack of envelopes on a firm
surface and press down firmly on the edges
to make the folds crisp.
§ Press around the envelopes to remove and
curls and expel air from inside the
envelopes.
§ Also, press firmly on the area that
corresponds to the edges of the flap.
6. Insert the envelopes
§ Slide the stack of envelopes into the sheet
feeder until it stops.
§ Align the stack of envelopes with the right
edge of the sheet feeder.