Brother Copier/Printer MFC-9970CDW - Manual (Page 30)

Chapter 2
14
d
Lift up the support flap to prevent paper
from sliding off the face down output
tray, or remove each page as soon as it
comes out of the machine. Printing on envelopes and thick paper
from the MP tray
2
Before loading, press the corners and sides
of the envelopes to make them as flat as
possible.
a
Open the MP tray and lower it gently.