With these TWSBI pens - it's a Taiwanese brand - the clear barrel is full of ink, and you can see the ink and how much is left. It sloshes around in the barrel and I think that is very pleasing.
for the middle two pens i matched the ink color to the end & cap color of the pen. deep geekery
it is the most simple pleasure, how the ink works, how it goes onto the paper, how deep and varied the colors and inks are. i wish i could draw