Hi All I currently use an undetermined diamine blue colour (kind of blue black), and as I move the ink around in my VAC700 demonstrator, droplets and smudges are left behind. I know the interaction between barrel material and ink chemistry is complex, so I’ll address my question only to TWSBI owners. Does any TWSBI demonstrator-owner happen to have a blue black or similar colour ink that does not leave such droplets behind? (Does that even exist?) Please share your pictures! Thanks! Bart