Here’s one of the kinds of things I loved coming across in books when I was a kid. This is probably a part of why I love drawing dungeons like I do, and that’s why I’m sharing it here.
I think this is a great resource. The full size plate is a thing of beauty. This came from the Gutenberg project, so it is a work in the public domain, and I’m happy to see it shared widely.
Already, this has figured into a couple of the maps I’ve posted (whether to good effect or not is a separate question), and I hope to do more from this chart (maybe eventually at least one of each, but there are no promises about that).
For reference, the kind of hatch that I do most often (and that Dyson Logos popularized) is #58, “Massive igneous rock,” but there are clearly other choices available, if you’re open to mixing it up a bit.