Abstract: A device (1) for supporting a stack of sheet material with zones of uneven thickness, e.g. envelopes (11), on a printer with a pick-up device (16, 17) for the envelopes and a table (10) is provided with a supporting plate (2) as well as bar type supporting apparatus (3,4) at the side facing away from the pick-up device (16, 17). The bar type supporting apparatus (3,4) may be swung away laterally for easy access to the envelopes. Furthermore the device (1) may be equipped with a base plate (36) having adjusting legs (37), for adjusting the device in a horizontal position on a slant table (10).