Sailor - Ukikusa (“duckweed”) is from their Manyo (“ten thousand leaves”) series of inks. It is a medium green, very natural-feeling, more leafy or mossy green than grass. It isn’t super saturated most of the time, so it seem a bit pale or muted rather than bold. It has plenty of shading, and although it doesn’t have any sheen, areas with heavy ink can get quite shiny.
Scans
There is some shading on each paper, but it shades the easiest on Iroful.
Photos
There isn’t any real sheen, but areas with very heavy ink get shiny in the large swatches.
No signs of the shininess in writing, but the shading looks nice. Though it shades the most on Iroful, I prefer how it looks on MD. It can be rather pale in the areas with less ink.
Microscope
Nothing too surprising under the microscope, though some hints of yellow show through on Iroful especially.
Chromatography

It starts with a large area of cyan, fades into a large area of yellow, then a narrow band of magenta at the end.

Under UV there is only a thin blue halo past the leading edge.
Verdict
This is a very good shade of pure “medium” green. It strikes a decent balance between light and dark green, though I personally prefer the slightly lighter and brighter tint of Diamine Apple Glory.
I’ve been using it for 5 months in a Jinhao 20 for occasional use (3 refills in that time, almost due for a fourth) and it’s done quite well.
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