Hi! Thank you! :D Instagram is just easier to post to, and I get much more likes and feedback there. On tumblr I always felt that since I’m not into fandoms, nobody is interested in my stuff here. Х)
As to the inks, I actually mostly use normal fountain pen inks that have some water resistance. So they bleed when water is used on top of them, but not disappear completely. My favorite brown ink, which I use alone and with watercolor as well, is J.Herbin Lie de The. It’s tea-colored, and when water is used on top of it, it bleeds with a rusty orange color, and the gray line is still visible. I love this effect and use it.
This is what I’m talking about:
https://www.instagram.com/p/5dMV9LA2lt/?taken-by=vorona.nanetta
https://www.instagram.com/p/8Tp_4dA2us/?taken-by=vorona.nanetta
I use other inks this way too. Lamy black is my favorite black for this technique. My favorite “normal black” J.Herbin Perle Noire is too concentrated for this. So, I love such inks for what they are. If they were completely water resistant, they wouldn’t be half as fun for me. :D What I don’t like is the inks that dissolve completely without a trace, and that’s the majority of fountain pen inks. :))) I try to avoid them, but they are just too nice sometimes (like Montblanc Toffee). :3
As to completely water-resistant fountain pen inks, there are two types: the ones that become water-resistant on paper, and pigmented inks. The first category is many of the Noodlers inks (like Noodlers Black, Lexington Grey and others in different colors). If you can order them from USA, I suggest you google them and try Noodlers Black at least (it’s very popular among sketchers, and lightfast as well). I’m far from USA and ordering is pretty expensive, so I tried only Lexington Gray. It was really completely water resistant, but I just didn’t like the color, and my Safari didn’t like the ink, started skipping soon.
As to pigmented inks, in general they are bad for fountain pens, but there are some that are produced specifically for fountain pens. They can be used normally (maybe not in your most precious pens), but you should clean the pens more often and not let the ink dry in the pen (!!!). I actually let some De Atramentis Dokumenten inks dry in my Safaris and Al-Stars, and it was a pain to clean (and I can still see some lighter inks in Al-Stars’ transparent feed), but all my pens write normally after that. But they are Safaris, it’s almost impossible to kill a Safari. :))) I didn’t use my pigmented inks in any other pens for fear of ruining them. So, other than De Atramentis Document (Dokumenten) line, there’s also Platinum Carbon Black and Sepia, some Sailor inks, Montblanc Permanent Black and Permanent Blue, Rohrer and Klingner Dokumentus, and some others that I don’t remember. The thing about pigmented inks is that they mostly feather very much (the lines are thicker and sometimes hairy) and they often look flat and opaque compared to normal dye-based inks. But some are better than others, do your research if you are interested! Here is the best place to search that I know of: http://www.fountainpennetwork.com/forum/forum/140-inks-inc/ I personally use De Atramentis Dokumenten Brown, and it’s very well-behaved warm reddish brown, although not as beautiful for me as some of my dye-based browns. And a fairly recent addition is Sailor Storia Lion, it’s a Quin Gold color and pretty nice and transparent, my Safari also likes it so far. :) Here Sailor Lion is on the foreground: https://www.instagram.com/p/BHXt4Yvjjbk/?taken-by=vorona.nanetta
(There are also iron gall inks, they are very water-resistant but strange, they become gray with time (like, months) in complete darkness as well, because of the oxygen in the air. My iron gall inks shade too much for drawing, the color change is unpredictable, and they are very non-lightfast, so I don’t recommend them for drawing.)
I’m sorry for the long text, but it was quite a big question. :)) I hope you find it useful!