Canon BJC-250 - Manual (Page 29)

Setting the Paper Thickness Lever
To ensure trouble-free paper handling, you'll want to set the paper thickness lever before
loading paper.
Set the lever according to the thickness of the paper you are using:
Left
Plain Paper
High Resolution Paper
Bubble Jet Paper
Transparencies
Back Print Film
High Gloss Film
Right
Glossy Photo Paper
Banner Paper
T-Shirt Transfers
Greeting Cards
Fabric Sheets
Other heavier-weight print
media
Envelopes
Be sure to check this lever before and after printing on heavier-weight print media or
envelopes.