A printing system for applying a coating product to an object to be coated, the printing system comprising: - a print head for applying the coating product to the object to be coated, the coating product flowing in a so-called normal flow direction; - a single filter positioned upstream of the print head to filter the coating product; - a plurality of valves and conduits adapted to convey the coating product, a filter flush fluid and a print head flush fluid, said plurality of valves and conduits being arranged to form: ∘ a coating product supply circuit; ∘ a filter circuit adapted to convey the coating product through the single filter in the normal flow direction and to convey the filter flush fluid through the single filter only in the direction opposite to the normal flow direction; ∘ a head circuit adapted to convey the coating product and the print head flush fluid through the print head in the normal flow direction; - a supply filter isolation valve configured to: ∘ in a closed state, isolate the supply circuit from the filter circuit; ∘ in an open state, connect the supply circuit to the filter circuit; - a print head-filter isolation valve configured to: ∘ in a closed state, isolate the filter circuit from the head circuit; ∘ in an open state, connect the filter circuit to the head circuit; system wherein the filter circuit further comprises a filter flush valve arranged vis-a-vis the print head-filter isolation valve and a filter purge valve arranged vis-a-vis the supply filter isolation valve and wherein the supply filter isolation valve, the print head-filter isolation valve, the filter flush valve and the filter purge valve are two-way valves. - a print head for applying the coating product to the object to be coated, the coating product flowing in a so-called normal flow direction; - a single filter positioned upstream of the print head to filter the coating product; - a plurality of valves and conduits adapted to convey the coating product, a filter flush fluid and a print head flush fluid, said plurality of valves and conduits being arranged to form: ∘ a coating product supply circuit; ∘ a filter circuit adapted to convey the coating product through the single filter in the normal flow direction and to convey the filter flush fluid through the single filter only in the direction opposite to the normal flow direction; ∘ a head circuit adapted to convey the coating product and the print head flush fluid through the print head in the normal flow direction; ∘ a coating product supply circuit; ∘ a filter circuit adapted to convey the coating product through the single filter in the normal flow direction and to convey the filter flush fluid through the single filter only in the direction opposite to the normal flow direction; ∘ a head circuit adapted to convey the coating product and the print head flush fluid through the print head in the normal flow direction; - a supply filter isolation valve configured to: ∘ in a closed state, isolate the supply circuit from the filter circuit; ∘ in an open state, connect the supply circuit to the filter circuit; ∘ in a closed state, isolate the supply circuit from the filter circuit; ∘ in an open state, connect the supply circuit to the filter circuit; - a print head-filter isolation valve configured to: ∘ in a closed state, isolate the filter circuit from the head circuit; ∘ in an open state, connect the filter circuit to the head circuit; ∘ in a closed state, isolate the filter circuit from the head circuit; ∘ in an open state, connect the filter circuit to the head circuit; system wherein the filter circuit further comprises a filter flush valve arranged vis-a-vis the print head-filter isolation valve and a filter purge valve arranged vis-a-vis the supply filter isolation valve and wherein the supply filter isolation valve, the print head-filter isolation valve, the filter flush valve and the filter purge valve are two-way valves.