Printing apparatus, control method thereof, and storage medium to reduce a size of a printing apparatus without a deterioration in productivity of double-sided printing

A method of controlling a printing apparatus having a supply unit configured to supply a print medium, a supply path configured to convey the print medium supplied from the supply unit, a first conveyance path configured to convey the print medium from the supply path, a conveyance roller provided on the first conveyance path and configured to convey a print medium in a first direction, a printing unit provided on a downstream side of the conveyance roller in the first direction and configured to print an image on a first surface and a second surface on a back of the first surface of the print medium conveyed to the first direction, an inversion roller provided on the downstream side of the printing unit in the first direction, and configured to convey the print medium in a second direction different from the first direction, and a second conveyance path configured to branch from the first conveyance path at a branch portion between the printing unit and the inversion roller and to convey the print medium conveyed in the second direction by the inversion roller from the branch portion to an upstream side of the conveyance roller in the first direction, the method comprising:

• conveying, in a case of performing printing on both sides of a plurality of print media, the plurality of print media such that a first print medium supplied from the second conveyance path and a second print medium supplied from the supply path overlap between the conveyance roller and supply path.