Several years ago, I had the opportunity to test a LOT of different colors/brands of fountain pen inks. (over 100!) Because I am a visual person, the best way for me to compare and contrast was to perform ink swatches and though my method was simple, you can make this process as detailed as you’d like. In the images I’ve attached here, I used cotton swabs to do 1, 2 and 3 swipes of each J. Herbin ink in a white drawing pad.
I also kept two separate journals that I only used for ink testing. One with white paper and one with ivory.
What process do you use to remember what all of your inks look like?