Once the design and colours have been finalised and approved by the client, the design goes through a process where it is reproduced on a full sized screen. A positive to positive opaque image is printed on clear film. This is then used to reproduce the design pattern on the emulsion by exposing the screen to light which makes the emulsion water resistant where there is no image layer. The water soluble parts are then washed off the screen. It is checked for quality and then passed as ready for printing.