The invention provides the means and the methods for the production of arrayed experiments on a substrate using the principle of a movable type printing press. This allows an entire array comprising a plurality of experiments to be printed simultaneously on a substrate. This is achieved using a plurality of tubes aligned within micro-engineered printing plates. Each printing plate comprises a line of capillaries embedded within the plate, where they can articulate vertically when the tubes contact the substrate. To construct the print face, the method provides the means to stack multiple print plates into a print face, thus comprising many capillaries ordered in an array. Also provided are the means to manually or fill the capillaries using a micro-fluidic plate, and the means to ensure repeated efficient cycles of printing through the principle of a returning plate. The method thus provides the means to assemble and print arrays of experiments from a movable type face in a single contact with the substrate. The invention extends to a printing apparatus, a method of printing a layered array of spots of reagent compositions, a method of introducing reagent compositions into the tubes, a reagent introducing device for introducing reagent compositions into the tubes and a printing installation which includes the printing apparatus and the reagent introducing device.