Blue #4 is very similar to Blue #1, except that it dries a little slower, is slightly more lubricated, and doesn't have as much of a dramatic color-changing drying performance. Still, for all the similarities, it's the color that certainly sets this one apart from its sibling.
Let's cover the similarities first. Iron gall? Check. Dries darker than the original wet color? Oh yes. Water resistant? You bet. Easy to clean out of a pen? Definitely.
Now, let's talk a bit more in depth about the differences in Blue #4. For one, this ink is slower to dry than Blue #1. Average dry time for #4 is around 30 seconds, compared to 20 seconds for #1. 30 seconds is a bit on the long side for my tastes, so that's not something I can get over quickly.
Blue #4 can exhibit some nice shading behaviors — nothing extreme, but definitely pleasant. You'll notice it more after the ink dries since the wet ink is a pretty flat color. Like its #1 sibling, #4 also performs at an excellent level where show-through, feathering, and bleeding are concerned. Seriously, these KWZ IG inks are champs in this regard.
One thing that I definitely enjoy in this ink is the fact that it's less dry than Blue #1. It's certainly not a wet, easy-flowing ink, but it feels more normal when writing. Or, put another way, the pen/nib that I'm accustomed to still feel like the same pen/nib. With Blue #1, I hardly recognized my pen due to the significant drag on the nib from the dry ink.
Finally — possibly the most important attribute of the ink: the color. When writing, the color is a dusty purple with some distant blues shimmering through. As the ink dries, it transforms into a dark purple. It's a beautiful color once it dries, but I'd argue it's far from any blue I've seen. In certain spots, I can make out a dark, dark gray-blue, but my eyes still refuse to see anything but a purple foundation. Who knows, it may just be my unique eyes and a problem with how I see color (that's the funny thing about colors, anyway - we all see them differently to some extent), so take my opinion with a grain of salt.
That said, I like the color quite a bit. It's not what I recognize as blue, but that doesn't mean it isn't an intriguing, beautiful color.
There's a lot to like about these KWZ Iron Gall inks. What it really comes down to is your color preferences. Like the Blue #1 I tried before, Blue #4 offers some fantastic characteristics, and my favorite one by far is watching the color turn darker as the ink dries. If that sounds interesting to you, you really need to try out some KWZ IG Inks.
(Vanness Pens provided this ink sample at no charge to The Pen Addict for review purposes.)