Canon iR3245 Manual page 181

If you select [Double] (Left):
If you select [Saddle Stitch]:
Remark
If the optional Finisher-S1 is attached, you cannot
select the stapling position. For more information on
stapling positions, see the Reference Guide.
The accuracy of folds created in the Saddle Stitch
mode may vary, depending on the paper type and the
number of sheets.
If No Finishing Mode Is Set:
If the Collate, Group, and Staple modes are not set, copies are output as follows:
To use the Saddle Stitch mode, the original (stored
document) must already be in booklet form, as shown
in the illustration above. (See "Booklet Mode(p.4-12).")
Collating Copies
3
3-31