Thickness (graph theory)

Summary

In graph theory, the thickness of a graph $G$ is the minimum number of planar graphs into which the edges of $G$ can be partitioned. That is, if there exists a collection of $k$ planar graphs, all having the same set of vertices, such that the union of these planar graphs is $G$, then the thickness of $G$ is at most $k$. In other words, the thickness of a graph is the minimum number of planar subgraphs whose union equals to graph $G$.