COATING
RODS The preferable alternative when using some sensitisers, particularly platinum and palladium, where a substantial amount of very expensive sensitiser can be left unrecoverable in the brush. A syringe is used to lay a line of sensitiser onto the paper, and the rod is then touched down onto the paper at this point. It can then be drawn down the paper, pulling with it the reservoir of liquid. The amount of sensitiser should be calculated to be absorbed after about 5 passes, and the result will be a carefully metered application of sensitiser over the selected area. However, the only choice over coating width is the width of the rod, and for this reason several are offered. Now in unbreakable plastic, turned at the end to provide handles.
