Really love the fine-tip ink look! You could mirror these on OpenGameArt too, they're proper brilliant as CC maps.
Index Card Dungeon Project
A downloadable map project
This is a set of eighteen dungeons I drew on index cards, mostly while traveling in 2014. They're scanned from white 3"x5" cards, drawn primarily with Micron pens and fine-tipped Sharpies. I even had a little art show with them!
Anyway, they're yours to enjoy, and free to use with attribution under the CC BY 4.0 license.
Click download now to get access to the following files: