type: double, default: 1.0, minimum: 0.0
including the boundaries of edges and clusters.
penwidth value is inherited by subclusters, and has no effect on text.
Previous to 31 January 2008, the effect of penwidth=W was achieved by including setlinewidth(W) as part of a style specification.
If both attributes are set, penwidth will be used.
© 2025 The Graphviz Authors
Licensed under the Eclipse Public License 1.0.
https://www.graphviz.org/docs/attrs/penwidth/