Today, I found what was probably mold on the Kuretake No. 33 disposable brush pen I refilled (and like an idiot, I didn’t take a picture of it). Whatever it is, it’s gone for now—wiped away, doused in rubbing alcohol (please note that I don’t know what I’m doing, but considering it’s supposed to be a disposable pen, I feel free reign to experiment with its health), subdued for the time being.
The ink in it has had a long history in which contamination could have been introduced—it came from a bottle of Noodler’s Bulletproof Black from 2010, poorly shipped by Amazon, cap busted in transit, had to find a new container for it. The first container was apparently only intended to be airtight for herbs/spices, not liquids, so I had to further transfer the ink into several small screw-top containers (bought new, they are intended to hold paint). And then, to fill the Kuretake, I left the ink sponge cartridge propped upright in the open little container overnight (capillary action takes a little while) before popping it into the pen. Before discovering that mold today, I probably hadn’t used the pen in a couple weeks, and I’ve never had any problems with any Noodler’s ink before—in this case, I think we can safely blame the hard life of this particular sub-bottle of ink (I have an eyedropper filled from a different little container, same ink batch, haven’t used it in probably the same amount of time, and it shows no problems at all).
Now, I know better than to leave fountain pens full of ink sitting unused for extended periods of time. I know I need to clean them out if I’m going to store them. But I have had multiple ink brands (Lamy, Noodler’s, Sheaffer, Rotring, J. Herbin, Kaweco, Monteverde, Pelikan all jump to mind) give me no problems even when I’ve stupidly left them sitting unused in a fountain pen for over a month or more (shame on me, I know, I know). The worst I’ve ever had with any of those is that the ink just dries up—you clean it out with a bit of water, dry it off, good as new. The only exception to this trend has been the creeping colored crud unique to any pen I’ve left unused with Private Reserve ink in it.
No other brand does this. Only Private Reserve, in my experience. I’ve had it happen with Private Reserve bottled ink and cartridge ink. Had it happen with Buttercup yellow (victim: Pelikan Griffix 4), Dakota red (A. S. Spalding & Bros Mini Pen), Avocado (Muji Fountain Pen), Ebony Blue (Muji Fountain Pen again, I think), Black Cherry (Schrade Tactical Fountain Pen)….and that’s just the ones that I remember (I’m sure I’m forgetting some). I don’t know what it is, exactly; after cleaning with water (will usually leave the nib and feed in a cup of water to soak overnight), the pens have been fine. No resurgences of crud (excepting when Private Reserve ink was used again in the pen). Whatever it is, it looks exceptionally gross (you try uncapping what is supposed to be a kid’s pen only to find what look like a bunch of little lichen cheese puffs all over the nib and crusted around the feed, and pretend like you’re gonna sleep okay at night), and it’s a big pain to deal with.
So remember, kids: clean your pens, use them frequently, follow proper storage protocol, and don’t buy Private Reserve Ink.