Today I have tried out watercolour on the previous sketch that I have drawn using the preppy disposable blue fountain pen. The nib I used is the fine 0.3 .
Notice that after applying watercolour, the blue drawn line seems to fade. All the while, I thought that this is waterproof ink pen. But in actual fact, this is consider as water soluble.So if you are expecting the outline to be solid colour, you may not want to consider this pen with the existing ink cartridge that came with it. I am not sure if this pen work with other cartridge or not.
