Canon PIXMA MG4200 Series On-Screen Manual page 102

(2) Use the right paper guide
(3) Load the paper in the center of the front tray WITH THE PRINT SIDE FACING
DOWN.
Push the paper stack all the way to the back of the front tray.
(4) Slide the right paper guide
paper stack.
Do not slide the paper guides too hard against the paper. The paper may not be fed properly.
Important
Always load paper in the portrait orientation (B). Loading paper in the landscape orientation
(C) can cause paper jams.
(A) to slide both paper guides all the way out.
(A) to align the paper guides with both sides of the