This is a topic I've been invested in for a while! It started years ago with Noodler's Heart of Darkness. Rejected, not because of the reaction with water, but because it feathers quite a lot, especially on bristol paper. I like SketchINK, but I also have a cartridge of Platinum carbon to properly test. (I wasn't fond of the pen because of the broad, stiff nib, but I'll hand it to Platinum: after months of sitting in a drawer, that pigment ink still flowed through it!)

I must try one of those De Atramentis inks, they look good. Thanks for showing them off.