Originating during the Restoration Cambridge style (so called because in the early years of the 18th century the Cambridge binders loved to do it and did it enough to get the appellation) is a calf binding with paneled sides, with the center panel and the border mottled or sprinkled. The style was also, more descriptively, called Cambridge panel.
This video, with appropriate musical accompaniment shows exactly how this was/is done. The craftsman makes it all look so easy. Maybe in the 18th century a toothbrush was not the favored tool for sprinkling!
I think that you inevitably assume that the frame of lighter colored leather is a separate piece, let into the main covering. The tooling by pallet and roller encourages this illusion.
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