Lighter inks don't work
355848
I have a couple of these pens in black and loved them so i ordered this set. Not as happy with these pens soon of the colors are very light and 2 of the pens barely work at all
4187761
I should have read the other reviews before buying. I have tried everything to get the color cartridge to work, and I have not been successful. The black worked just fine, so I am assuming the colored one is defective. Won't be ordering ink from Amazon again.
1105025
Skippy ink and not opaque. Will not write on black paper.
4389667
Black ink worked fine, but colors kept having issues and would not work.  Don't waste your money.
4385570
The colored cartridges worked but the black ones didn't. We tried multiple cartridges and still didn't work.
4893603
In spite of the ink levels showing half-full or better, they stopped printing shortly after I got them.  I tried all the cleaning techniques I could find to no avail.
4211710
Same complaint as the others.  So, how can we receive credit or replacements when the return window is closed? I just want ink that works--no prying faceplates apart and getting ink all over the place (and me!)
1555551
The sponges don't absorb the ink. Mine have been sitting almost two weeks and the ink refuses to soak in because of the sponge that's inside. The only one that worked correctly was the magenta one.
4560845
These work fine- but I can't use the ink for any tattoo stencils, for some reason won't pick up this black ink in our thermofax machine. Had to go back to the HP cartridges.
4609245
printer is not printing well, so light and in a light yellow color, not sure if it is the ink.  Will not print in black and white, this just happened with the ink I ordered here.
3482374
I tried all the ink saving options I could but I can't get one of these things to last more than 40 to 50 pages.  Quality all the way down, fastest settings, lightest ink density, none work.
2714190
In January I bought this set because I wanted a more "reliable" and high quality pen to do my art with. Everythingff great, I got my pens on time and I was able to assemble them with no problems. However, the day after I assembled them, the .10 stopped working. I haven't been able to get that one working since. Then about a week later, the .30 stopped working. I tried everything to revive both of these pens. I soaked them in hot water for hours, and spent countless more hours researching other methods to fix them. I was able to get the .30 to work temporarily many times. The ink would flow out of nib too quickly and make large puddles on the paper. It would only take a few minutes before the ink stopped flowing again.  The .50 has been the only one that works, it has no problems (at the moment).

I am very disappointed with these pens (.50 excluded). And I wish I had chosen a different brand to go with. These pens were, for me, a very expensive purchase and it seems that the only way to fix them is to spend more.
4478904
The red doesn't work. Other colors will kinda come out... after about 200 pages I think they stopped printing. :(
850755
I'm disappointed in these ink cartridges. I've printed maybe 15 basic (mainly black) pieces of paper and the magenta color is already gone. It must be faulty b/c it's barely been used. I'm printing on an HP Photosmart 6520 printer.
4522607
Spare inks aren't suitable for pen by size(shorter) and form(spring is freely moves along ink).
687465
I used these inks for professional prints and the colors were really off, though mainly the magenta. The magenta came in separate packaging and the cartridge looks different from the rest, so that may have to do with that. Besides that though, ink will sometimes leak and drip onto the page noticeably even on dark areas. I have also had multiple instances of the printer refusing to work with the ink which takes some work to fix.
3085698
I couldn't get these to write at all. Tried tapping them lightly. When a little ink would come out, it did not show up on the dark surface.