This pen works really nicely, but you just have to treat it well. It states not just on this website but on the side of the pen to replace cap firmly, and keep it stored HORIZONTAL. You must shake it with the cap on, because if you don't, white will get everywhere, as well as clean the tip after you are done using, so excess ink does not dry and cake up the nib.
This is a really great pen to use, especially if you like using white gel pens but don't like the uneven/unopaque look of them. This pen puts white down evenly, and pretty opaque, but for full opacity I would reccomend a second time over, and it layers perfectly with no "cut" through the middle, unlike white gel pens. This is a bit pricey but you just gotta treat it well, and it will treat you well back.

I'm a big fan of the Signo white gel pens, but they are best for final touches. They are very opaque, but they are raised off the surface of the paper, and once dry you can't really re-work the same area again without making a mess.

My first impression with these pens is very positive. Although these are a bit less opaque than the Signo's gel ink, it seems like you can layer these as much as you want - and you can even use them to correct inking mistakes. They take a while to dry, but once dry they are not raised off the paper's surface, which I love. I'll definitely be buying these again.

I really liked this pen! I like how thin you can get with it and the consistency of it taking in consideration other white ink pens. I gave it only three stars because it runs out of ink ridiculously too soon for the price. In my book, it is not worth it!

This pen sets itself above all the other pens I've tried by actually performing how it is described to perform. It is apparent a little maintenance is required, but this pen performs so well and the lines are so crisp and clear, that makes up for any cleaning required. An unlike gel pens, there are no streaks in the middle of your strokes and it doesn't gum up and dry out at random.

Good pen! I think you'll like it.

It can get messy but will do the job well. Just follow the handling instructions on the side of the pen and you should be fine. This replaced the 'Uniball Signo' in my daily sketching kit. Really great consistent line quality without a raised surface makes scanning and cleaning up artwork easy.

Works nicely over:
-'Pigma' Micron ink,
-'Pentel Pocket Brush' ink,
-'Noodlers Polar Black' ink used in a fountain pen
-Windsor & Newton' watercolors when dried.
-I also used this over 'MT' washi tape for project once and it worked great!

Wiping down the cap and tip every now and then helps to keep the dried ink from building up and saves you from being spattered with loose ink when you open it up.
I also try and blot the nib on some clean paper when I'm done using it but that's probably over-kill.