Marbled paper- double comb

The following endpaper is found on a book published in 1866, by Routledge. It is of a pattern that is known as the "double comb".

 

As you can see, this pattern is a variation of the nonpareil pattern http://decoratedpaper.blogspot.sg/2013/08/marbled-paper-1-nonpareil.html . The difference, however, is that an extra step is required in this pattern. In a nonpareil, the colours are manipulated by with a comb-like device. However, in this pattern, an extra comb, with teeth of different width, is then used, resulting in the effect you see here.