Excellent Pigment Ink
This is my first bottle of Sailor micropigment ink and it has really impressed me! It's been in a Metropolitan with an EF nib for over a week now, and there have been no issues with clogging or hard starting, which I was worried about with such a fine nib. It behaves like any other ink I have from Sailor, which is to say very well.
There is some shading on all paper types I have used. It is very waterproof, and very resistant to smudging after it's dried. Pretty impressive ink overall. Love the blue-black color.
Souboku Ink Bottle
This is my all time favorite ink and my daily driver in my Sailor King of Pen Medium (stock nib). The ink is a pleasant shade of blue-black that is both professional and exciting. Normally I use this ink on Tomoe River 58 gsm. On this paper, the nib is prone to some shading. I recommend agitating the ink before use!
I find the ink a little bit more well behaved and consistent than its partner, Seiboku. Souboku is much more gray and Seiboku is more of a true blue. I think of Souboku as a grey-blue-black. Like a very dark thundercloud.
Of particular importance to my sweaty fingers..once Seiboku/Souboku are dried on Tomoe (maybe 30 seconds?) the ink is TOTALLY smudge proof (unlike Kiwa-Guro, with which I have experienced smearing).
Before COVID I would swim in a local gym and I would use this ink to write my swim sets on kokuyo paper. The ink would be right next to the pool and would by the end of my swim set the paper would be soaking wet/falling apart but the ink would be clearly legible/non-smeared. So...it really is waterproof. It is also relatively coffee resistant.
This ink demands to be used and I heartily recommend it and I have received several bottles of this ink from Anderson Pens and been happy with each one. Clearly, I like this ink and I always enjoy doing business with Anderson Pens. Very friendly and reliable company with caring employees.