Multiple possibilities
The technique of drawing on frosted cels had unlimited creative possibilities: pencil drawings could be combined; pastel could be added; paint could be applied to the smooth side of the cel; and so on. "The problem was that the manufacturers who produced these cels—which, of course, were made for engineers—began to make the frosted side smoother. This meant that the pigments no longer adhered as well as they did to the older, grainier cels. You could still find cels that resembled the original ones, but I had great difficulty making The Mighty River with this newer and less interesting cel, on which the colours appeared less vivid and the line, less vigorous."
F.B.
Drawing from the film The Mighty River.
Drawing from the film The Mighty River.