I recently used a sample of Iroshizuku kiri same and I loved it, but I have to wonder, before I buy a bottle, if gray ink is worth it. Isn't it just watered down black ink? I put two drops of Noodler's Heart of Darkness and mixed it with almost 1ml of water and I got something quite similar in color, although it is missing the warmth of kiri same. Just looking for any other thoughts on this, if anyone is able to justify gray inks. Kiri same is a really nice ink, so I may buy it anyway, but I can't get that nagging feeling out of the back of my mind that I could be much more frugal and just water down my black inks. Has anyone tried watering down take sumi?