QUOTE(blueiris @ Feb 9 2008, 05:00 PM) [snapback]509024[/snapback]
I don't have both, but my friend has the J.Herbin and I have the Caran d'Ache. I don't have the experience Taki has with both inks, but just based on my friend's and my dip-pen comparison (done a while ago), I agree with Taki that they're quite close. From memory, I might say that the Storm is slightly, very very slightly less reddish than the Poussiere de Lune, but I wouldn't have noticed it if I weren't trying so hard to tell them apart. I'm sure I would have thought they were the same ink if I didn't already know which written sample was which. Neither of them are bright inks, and they both have a "dusty" or muted quality to them, if that's what you meant by "powdery."
That's pretty much my experience, also. When I first got a bottle of the Storm, I did do some side-by-side comparisons with Poussiere de Lune, just to convince myself that there was a difference between the two. Storm has that bluer tint, which I prefer, but I think that a non-fountain-pen person wouldn't be able to distinguish between the two at a glance. Storm is more water-resistant, and in some pens the color darkens after it sits in the pen for awhile. It's one of my favorite colors. (I still like my bottle of Poussiere de Lune also. Glad you are enjoying yours!)
Next on my list is Montblanc Violet, as I think it will fit my recent longing for a very dark purple with reasonable water resistance. (By the way, my own bottle of Waterman Purple has too much red in it, sort of a medium at best cheerful Easter Egg purple. I still seem to veer more toward the blueish purples, vs. the burgundies. The Peartree Pens sample of Noodler's Nightshade was from the more browny burgundy batch, unfortunately. I liked it but it was not what I was looking for. Love that ink sampler program!)