My fountain pen recently ran out of ink and i decided after cleaning it that now is a great time to mix some inks and try to find a new color i like. So i picked up a bottle of red (Corail des Tropiques) to go with the green (Vert Olive) and blue (Bleu des Profondeus) i already had. The photo above shows the colors of these inks, alone and mixed.
In case my handwriting isn't clear enough, on the right of the page (top to bottom) are Vert Olive, Bleu des Profondeurs, and Corail des Tropiques. All from Jacques Herbin, since i thought it would be safest to not mix different brands. On the left are green & blue, blue & red, red & green, and then all three mixed.
The green & blue mix has a bit more green than blue, and the blue & red mix has more blue than red. Still, these turned out to be harder than i expected to measure precisely. I guess that comes down to me using a pipette instead of an eyedropper. I just mixed the inks in three small jars, two colors in each jar, and then painted them onto a piece of cardstock with a small brush. The last one was done by mixing the three test jars after i had samples of each.
My favorite of these is the purple i got from blue and red, followed closely by the dark gray from mixing all three and then the darker green from green and blue. Blue alone is also fine, but i don't care for straight green or red, or those two mixed.
Purple was the least surprising result. I figured green and blue would make something more like teal. Maybe they would have had i used more blue or started with a darker green. The brown i got was more orange than i expected, again because the olive green is so close to yellow. What surprised me most is what i got mixing all three. I assumed i would get a muddy brown but it came out as a lovely light black^1^ instead. Reminds me of storm clouds in low light.
I did ask at my local nice stationary shop about mixing inks, but nobody working then had done it before so all they could say is that it would probably be fine. They did wonder if the inks would mix completely or if i'd end up with a multi-color ink that changes as i write. That didn't happen, they mixed very easily. I could probably get a multi-color ink if i just added different colors to my pen without first mixing them, but they'd still mix together over time and as the pen moves. I imagine marbled ink would work better for a dip pen that can write without stirring up the ink much.
Filling the pen
Filling the pen with my new purple ink was harder than i expected. The jar i mixed it in was too wide (and thus too shallow) to fill it normally. I have a TWSBI Eco so the normal way is to stick the head of the pen into a jar of ink and draw it up with a plunger on the back of the pen. Instead i took the plunger mechanism out of the pen and filled it there with a pipette. I had the pen sitting nib-down in a jar of water in the hopes that that would help stop ink from leaking out before i got the plunger back on. It did not, and also some water got in and i had to scribble for a minute to clear the watery ink and get to the stuff that's visible. What i should have done is set the pen in the jar of ink i was filling it from, so any leaked ink would not be wasted. But now i know for next time.
Notes
^1^ I distinguish dark and light gray from light black and dark white. Dark white is the color of snow at night, light black is the color of an overcast night sky lit up by light polution. Light gray is the color of dusty gravel or clay, dark gray is the color of Batman.