|Image care of pentel.ca|
It is for these reasons that I am often on the lookout for a drawing pen that can give me a nice variable line, something that instantly has a bit of character to it. Tombow brush pens come close, but they are disposable and drain quickly. I have a similar feelings about Faber Castell Pitt pens, although I know of many people like Lucy Knisely and Adam Koford who use the Pitt pens with great skill.
I have recently revisited Pentel's GFKP brush pen. It has a flexible brush tip and can be refilled with specially made ink cartridges which are relatively cheap and seem to last for ages. The pen gives a nice lush line with an easy variability. The ink is dark and waterproof and can handle watercolour and ink washes over the top. On some types of paper the ink can take slightly longer to dry when heavily applied, but I have found this to be more about the paper than the ink used in the GFKP. The pen is a great way to start practicing inking with a brush before buying an expensive sable brush. You will probably end up liking it so much you will not want to even pick up a sable brush at all.
If you have used the Pentel Aquash before, the GFKP pen is a lot more controlled and better for finer more accurate inking. I still like the Pentel Aquash, but I find them better for ink washes rather than detailed inking like the GFKP.
I feel like I still have a lot to learn about inking with the GFKP, partly this is learning to control it better and partly it has to do with inking with a brush. Although you get that lush line, you do not get the same friction from inking with a pen. I must say there is something nice about fighting with paper and feeling the pen scratch and dig as it moves around the page. But for now this pen is the closest thing I have to my perfect inking tool, portable, refillable, and a variable line with waterproof ink.
You can find the Pentel GFKP online through jetpens.com I have ordered from jetpens a number of times and they have a range of excellent products and quick delivery.
Here is a comic I drew with the GFKP here, and another one here