The action of the aquatint booths in the SK-series is based on the hand driven paddle wheel. Also this huge aquatint booth has this system but adapted to its size; one crank handle drives two shaft with each a paddle wheel. (turning ratio 2:1) This traditional method is still able to guarantee the most even distribution of rosin on the plate. The agitator is driven by a turn handle from the outside. This model (like the SK-80's) features a wooden grill that slides out to facilitate plate insertion and retrieval. The aquatint booth's are constructed of plywood and varnished.