Brother HL 4570CDWT - Manual (Page 66)

Driver and Software
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2
 For Mac OS X 10.5.x and 10.6.x
a Select Layout.
b Choose Long-edge binding or Short-edge binding in Two-Sided. Automatically the Two-Sided
check box is checked.
c Select Paper Handling.
d Choose All pages in Pages To Print and click Print. You can print pages on both sides of the paper.