This ink is an unusually bright cold-red, red-violet comparable to Noodlers Socrates in color, but much denser. I use this ink sparingly in sketches due to the brightness. As with all R&K Sketch Inks, suggest mild shaking before inking and while in the pen before writing. The nano-pigments of Vroni are staying in better in suspension compared to Lotte (black). I am currently testing several R&K sketch inks for UV Sun fading and rain-water resistance on Rhodia Dot Pad #18 paper. So far all sketch inks are passing, but time will tell (28 day test). There is no pen clogging so far in Pentel Tradio (broad nib).