Hello BrassRat, et al,
I started by adding 1 drop of glycerin per 1 oz. of ink... shook the bottle... dip tested it, using a fountain pen and kept adding one drop and shaking until I got the feeling I was looking for, (2 drops in a bottle J. Herbin brown... it's slipping my mind right now, which one).
Thank you for the detail, Anthony. Looks like I'll need to experiment, looking out for drying time on paper as the possible downside.
The catch... or down side is that if you favor wide medium and broad nibs, (like yours truly); or if you're using stubs, italics and especially Flex nibs, (which all require heavier flow rates), the diminished flow can be problematic.
The too-wet pen that prompted my question is a Lamy 2000 cursive italic. A diminished flow rate with inks I like is the goal, not the problem. Nib tweaking only got me so far; flow is about right with Pelikan 4001 Blue-Black, but ... .
Relative flow rate -- quantity of ink deposited on paper -- is what I meant by "dry". Lubrication feel and viscosity and drying-time and maybe other things were not my focus, though those are included in what folks sometimes seem to mean by wet/dry. If I could have low-flow, saturated, lubricious, fast drying inks for that pen -- ah, bliss!