Cables are usually done in stocking stitch and surrounded with reverse stocking; this causes the cables to stand out against a receding background. But any combination will do; for example, a background seed stitch in the regions bounded by cables often looks striking. Another visually intriguing effect is "meta-cabling", where the cable itself is made up of cables, such as a three-cable plait made of strands that are themselves 2-cable plaits. In such cases, the "inner" cables sometimes go their separate ways, forming beautiful, complex patterns such as the branches of a tree. Another interesting effect is to have one cable "pierce" another cable, rather than having it pass over or under the other.