Thanks for posting your unintentional test results, karinh. I've read elsewhere on FPN that red inks have more of a tendency to stain pens as well. So, taking longer to rinse out certainly follows.
The drying time for these Pilot Mixable Color inks is really fast and the dye saturation appears quite high, similar to the Pilot Iroshizuku samples I have. However, I've no idea if they're at all similar beyond that. For all I know, Pilot may add some component to get that mixable effect that isn't fountain pen friendly. It's a shame fountain pen inks don't have the ingredients listed like some other products do. It would be fascinating reading. Wow, there's so much geek in that sentence that even my Type A Analytical Chemist mind boggles!
Thanks for the comment 777. I haven't tried switching cartridge colors with other brands, so the mixing effect may not be unique to these inks. However, The Pilot Parallel Pen Wizardry book recommends just placing one tip parallel nib down on top of another to mix inks. I haven't tried that, but the Parallel's nib design and proprietary cartridges dictates the Mixable Color line.
My one complaint is that the ball and washer design seems to be a problem when replacing these cartridges. If they don't reseat properly flow problems result. Also, I had trouble restarting the ink flow after leaving a green cartridge in my pen overnight. I'm not sure if it just didn't reseat correctly, or if it's simply an ink flow issue.
Finally, the ink in the first post is Blue Black. I just turned up a Blue cartridge. I'll get a scan of that posted next.
Edited by DilettanteG, 14 September 2010 - 20:23.