The specification discloses a waterbox for applying an aqueous mixture, such as a starch mixture, to a web in a calender stack. The waterbox includes a spillway disposed adjacent a calender stack having a bottom plate, substantially parallel front and rear walls, and substantially parallel first and second end walls. The waterbox also includes an elongate lip for which extends from adjacent the front wall of the reservoir to a position adjacent a roll of the calender stack to form a pond area. A weir is provided for controlling the amount of mixture in the pond. Additionally the waterbox includes an inlet or a plurality of inlets for introduction of mixture into the pond area located below the pond level.