I received samples of ink from Hieronymus Stationers Ltd. in mid February and my initial impressions of the inks that I received can be found here.
Hieronymus Violet 01 is a decidedly blue ink. The ink may have very slight purple leanings but no one would say that it has been accurately named. As blues go, it is fairly dark and some might consider it a blue black. Having said that, it doesn't skew grey which can be a characteristic of blue black inks.
Shading: I think that the shading shown on the writing samples has more to do with ink flow issues than an ink being formulated for shading tendencies. I don't consider this a good shader.
Bleed Through: Copy Paper experiences spot bleed through.
Show Through: Show through on Copy Paper is borderline and may be an issue for some users. Field Notes and Rhodia worked well with the ink
Saturation: I would consider this ink to be fairly saturated although the colour is muted/matte.
Water Resistance: This ink has fairly good water resistance.
Drying Time: Average, 20-25 seconds using an EF nib on Rhodia.
Flow: I found the ink to be on the dry side and flow to be restricted.
Colour Make Up
Of the inks that I have on hand, Pilot Blue Black is one of the better matches.
This is a pretty unremarkable ink. I can't find anything that would make me recommend it to a purchaser when inks that are 1/3 of the cost are better performers. Take the money that you would have spent on this and purchase a bottle of Pilot Blue Black, Waterman Mysterious Blue and Rohrer & Klingner Salix, you will come away with money in your pocket as well as three really good blue black inks.
For other reviews of this ink search Ian Hedley's Pennaquod search engine.
Hieronymus Stationers Ltd. provided the ink that was reviewed above. I do not feel that my opinions of this ink have been affected by receiving the samples free of charge.