Sailor Jentle Blue Black - 4ml Fountain Pen Ink Sample

Hue: A cool, desaturated slate blue-black. Sailor market it simply as blue-black, and most retailer copy describes it as a dark blue with black depth — my swatches read noticeably greyer than that. In the dip-pen bar and the writing sample it sits as a muted blue-grey with a faint petrol cast rather than anything close to true black, and the heavier muddler swabs deepen towards dark teal-slate rather than navy. Written down in a fine nib it will look darker and cooler than the swabs suggest.

Shading: Light to moderate. The dip bar shows a gentle light-to-dark gradient, and the writing sample shows soft variation at stroke ends rather than dramatic contrast.

Sheen: Yes — a strong coppery red-brown sheen wherever the ink pools. It's very visible on the edges and pooled areas of my swabs, and appears even at the puddled end of the dip-pen bar. In ordinary writing on absorbent paper you'll see little to none; on coated paper and in wet nibs it comes through.

Shimmer: None.

Flow: Wet.

The interesting bit: Jentle is Sailor's own spelling of "gentle", the idea being an ink that's easy on pens, and the line ran in these flat 50ml jars with a clever little reservoir insert — you push it down and it traps a small well of ink so you can still fill a pen when the bottle is nearly empty. Most of the Jentle colours were later folded into the 20ml Shikiori "Four Seasons" bottles, but the three workhorses — Black, Blue and Blue Black — stayed in the original 50ml presentation, which is what this sample came from. Blue Black is also the dye-based counterpart to Sei-boku, Sailor's nano-pigmented blue-black: same broad colour family, none of the pigment handling considerations.

This is a hand-decanted 4ml sample vial from my own bottle.

Photos are my own swatches on Tomoe River Paper.

I'm a collector and I'm always happy to talk ink, so please message me if you have any questions.