the best ink for Pentel brush pen (I used this ink for some other brush pens at
my own risk) and it is waterprooof and very dark which is not easy to find when
I wish Pentel would develop a grey version (same waterpoof type) of this ink to
be used with Pentel brush pen (they have the larger color petel brushes but they
are not waterproof). That would be cool for drawing.
Believe me, you are going to burn through those two cartridges that come with
your brushpen. Some stores only carry the two pack for the same price or a six
pack for 11.00. So this the better deal. Will go through jetpens.com in the
future to restock on refills.