A flat bed printing mechanism for a postage meter is disclosed which includes a flat printing die, a platen mounted beneath the printing which is movable toward and away from the printing die to as to bring the image area of a mail piece disposed over the platen into printing contact with the printing die. The platen supports a resilient pressure pad which contacts the mail piece, and there is a resilient means interposed between the upper surface of the platen and the lower surface of the pressure pad to support the pressure pad in spaced relationship with the upper surface of the platen so that the pressure pad is free to move both linearly and angularly with respect to the platen when the platen moves upwardly to press the mail piece against the printing die, to cause the plane of the upper surface of the pressure pad to conform to the plane of the image area of the mail piece as the platen pushes the image area of the mail piece upwardly toward the printing die.