Any map colour, or percentage of the same colour, required its own overlay sheet so that different printing screens could be introduced later in the production workflow. This type of work, before the introduction of clean and simple peel coats, was messy. In this example, the original scribed drainage sheet has been reproduced onto Astrafoil specifically to paint in the 20% blue drainage infill. A Graphos pen was initially used along these boundary lines to form an edge which was then carefully expanded into the infill area with a fine brush. Finally, much larger brushes, up to an inch wide, were used to complete the job. This method can clearly be seen here where the light catches the surface. Hausleither ink (which we referred to as ‘plastic ink’) was used on the Astrafoil, etching into the surface – a quantity of ink like this could take several days to completely dry.