Canon BJC-250 - Manual (Page 31)

Loading Paper
You can stack paper in the sheet feeder to load it automatically, or you can
manually feed one sheet at a time through the manual feed slot.
You place approximately 100 sheets of plain paper (20 lb. or 75 g/m²) in the
sheet feeder at a time.
You can stack approximately 50 sheets of Transparencies or 10 sheets of back
print film in the sheet feeder. However, these special media may not advance
correctly under unusual environmental conditions (such as extreme
temperatures or humidity). If you have trouble with special papers becoming
skewed or feeding multiple sheets, do not stack them in the sheet feeder.
Load them on sheet at a time.
Automatically Feeding Paper
1
Left for plain paper
Right for heavier-weight print media or envelopes. Set the paper
thickness lever.