The latest Field Notes ("Lucky") work pretty well with #fountainpens. Not the best for showing ink properties of course, but that's because it soaks in immediately and without feathering or noticeable show-through. And that's great, because it means 0 problems with smearing. I've been using a LAMY 2000 F with Diamine Velvet Emerald and now Teranishi Smoky Navy. Line width is a bit inflated but still clean.
@Anke Definitely! And the way I use them involves flipping back and forth between pages while writing, so there is great potential for smearage normally.
@johns "soaks ink up so it dries quickly" is a very sensical property for paper of field notes in particular!