A process for the patterning of a desired substance on a surface includes: (i) charging a vessel (12) with a compressed fluid; (ii) introducing into the vessel a first feed stream comprising a solvent and the desired substance and a second feed stream comprising the compressed fluid, wherein the desired substance is less soluble in the compressed fluid relative to its solubility in the solvent and the solvent is soluble in the compressed fluid, wherein the first feed stream is dispersed in the compressed fluid, allowing extraction of the solvent into the compressed fluid and precipitation of particles of the desired substance; (iii) exhausting components from the vessel (12) through a restrictive passage (16) including a discharge device (13) that produces a shaped beam of particles of the desired substance at a point beyond an outlet of the discharge device (13); and (iv) exposing a receiver surface (14) to the shaped beam of particles. |