Gel ink refills from Ohto that can fit all the Ohto Liberty pens such as the Ohto Fine, Orca and more. These refills are the same size as the C-30X (i.e. C-305, C-307, C-310 etc) Ceramic Roller Ball series and are interchangeable. The G-30X series has gel based ink instead of the water based ink of the C-30X line. 0.5 mm, 0.7 mm and 1.0 mm sizes available.
I have purchased three of these with poor performance upon receipt. JetPens
provided technical assistance immediatly to fix the problem.
The only issue is incomplete lines. As if the roller ball was sticking or the
flow of ink was stalled. This was more pronoun on scientific notebook use. It
did perform if the length of time on paper was short and the paper was thick.
If I could get this thing to work it would be perfect. I love the color and
line when it works.
End result = a bit of frustration and ~$20 down the drain.