Caneworking originally was a technique used by glass blowers.
A cane is made from rods of glass melted together to form a design that can be revealed when a cane is sliced. A cane may be reduced, which allows creating intricate designs with many details. Slices of cane are applied to a surface to form a pattern. The same technique is now used for polymer clay.
See also: Millefiori.
Please refer to my tutorial to learn how to make polymer clay leaf canes.