The invention relates to a system (2) for producing an optical mask (35) for surface treatment, in particular surface microtexturing, said system (2) comprising: a layer of material (20) which has an outer surface (21) that is exposed to the outside environment; and a generating and depositing device for generating and depositing droplets (30) on the outer surface (21) of the layer of material (20) in which a specific arrangement (31), forming the optical mask (35) on the outer surface (21) of the layer of material (20). The invention also relates to a treatment plant comprising a system (2) of said type. The invention further relates to a method for producing a mask as well as to a method for surface treatment.