An apparatus for creating a three dimensional fluidic device containing at least one fluid channel, the apparatus comprising: a dispensing head comprising a passage for receiving a supply of material, and comprising a dispensing orifice at one end of the passage; a base member for receiving the material dispensed from the orifice of the dispensing head; an actuator means for moving the dispensing head relative to the base member; and a controller for sending a set of predetermined commands to each of the actuator means and the dispensing head; wherein the apparatus is operable to create the fluidic device by depositing a series of sequential layers of material from the dispensing head onto the base member, each layer formed of a series of adjacent line deposits of material, based on the predetermined commands sent by the controller to the actuator means and the dispensing head, wherein the apparatus is operable to overlap the line deposits to reduce leakage paths between the line deposits to improve the sealing properties of the at least one fluid channel in the fluidic device; characterised by the predetermined commands from the controller include instructing the apparatus to dispense: a plurality of deposits of material forming the bottom portion of the perimeter wall of a fluid channel in the fluidic device in at least one of the layers of material; wherein the plurality of deposits of material are substantially parallel to the direction of fluid flow along the fluid channel when the fluid channel is in use. a dispensing head comprising a passage for receiving a supply of material, and comprising a dispensing orifice at one end of the passage; a base member for receiving the material dispensed from the orifice of the dispensing head; an actuator means for moving the dispensing head relative to the base member; and a controller for sending a set of predetermined commands to each of the actuator means and the dispensing head; wherein the apparatus is operable to create the fluidic device by depositing a series of sequential layers of material from the dispensing head onto the base member, each layer formed of a series of adjacent line deposits of material, based on the predetermined commands sent by the controller to the actuator means and the dispensing head, wherein the apparatus is operable to overlap the line deposits to reduce leakage paths between the line deposits to improve the sealing properties of the at least one fluid channel in the fluidic device; characterised by the predetermined commands from the controller include instructing the apparatus to dispense: a plurality of deposits of material forming the bottom portion of the perimeter wall of a fluid channel in the fluidic device in at least one of the layers of material; wherein the plurality of deposits of material are substantially parallel to the direction of fluid flow along the fluid channel when the fluid channel is in use. a plurality of deposits of material forming the bottom portion of the perimeter wall of a fluid channel in the fluidic device in at least one of the layers of material; wherein the plurality of deposits of material are substantially parallel to the direction of fluid flow along the fluid channel when the fluid channel is in use.