Only use the paper tray to print 2-sided print jobs manually.
Plain paper, Copy paper, Preprinted paper, Letterhead, Color paper, Recycled paper*1
Thick paper (91 to 160 g/m²)*1
Thick paper (161 to 250 g/m²)*2
*1A4, A5, B5, Executive, 16K, Letter, SP1, and user-defined size (148 to 215.9 x 210 to 297 mm) paper is supported for automatic 2-sided printing.
*2Manual 2-sided printing only.