A screening apparatus including a table for holding an article; and a dual reservoir dispensing assembly. The dual reservoir assembly includes first and second reservoirs for holding first and second materials to be dispensed; first and second nozzles in communication with first and second reservoirs, respectively, for dispensing first and second materials; tilting apparatus for tilting the nozzles in a first direction so that the first nozzle is tilted into position for dispensing the first material and for tilting the nozzles in a second direction so that the first nozzle is tilted out of position and the second nozzle is tilted into position for dispensing the second material; and apparatus for moving the dual reservoir dispensing assembly with respect to the table wherein, in operation, the first nozzle is tilted into position during a first movement across the article and the second nozzle is titled into position during a second movement across the article.