I reviewed Scribal's Siren Blue ink a few months back. I used this ink almost exclusively in my recent grad school class. Except when my pen wouldn't write because it had dried out.

This is a perfectly colored ink, PERFECT. I would buy this ink in a quart size if only it's flow and lubrication were better. This ink makes my normally smooth pens feel scratchy and like I'm wearing off the tipping. It also makes my wet pens feel like they flow erratically and slowly, making them dry writers. It also makes every pen I've had it in a hard starter, even the pens with air tight caps. Pens that I've never had starting issues with, start hard, and often need water added to the nib to get them going. Frustrating.

Here are a few thigns I've tried:
5ml ink + 10 drops water (poor)
5ml ink + 2 drops dish soap (poor)
Decant 5ml of ink into a small container, add .5ml distilled water and 2 drops dish soap.(winner) This last option makes the ink flow much better but has worse performance on bad paper- more feathering and bleed. But it starts better, though not well or perfectly.

I am considering adding 1ml Camlin turq to 5ml Siren or 1 ml blue quink to 5ml Siren to see what I get. As is, nothing can flow as bad as the Siren on it's own.

I love this ink's color and qualities but damn if I can't keep my pens writing in grad school I'm screwed!

***UPDATE***
Immediately after writing this I mixed 1ml camlin turq + 1ml Quink blue + 5ml Siren. The color is indistinguishable from the original and the flow is better, dry out is gone, and my pens no longer feel like they are being sandpapered. Winner. I immediately mixed up 30ml of this blend. It iwll be my go to ink for school. Now I need another bottle of Siren.