Here are 20 chromatograms of the Diamine inks I own (yes, too many). The process starts with a white coffee paper cut into an approximate rectangle, spotted with the ink of choice, and placed in a shot glass with water in the bottom:
Here are the reds and oranges. Left to right is Amber, Sunset, Deep Dark Orange (Cult Pens), Ancient Copper, Deep Dark Red, Oxblood and Red Dragon. Interesting how close some of the inks are. Also note the pink part of the chromatogram (a pain to flush out of a pen) and by contrast how well the red moves with the solvent front.
Here are some greys and blues. L-R it’s Graphite, Grey, Eclipse, Deep Dark Blue, Deep Dark Purple, and Imperial Blue (another pain to flush).
Remaining colours are Hope Pink, China Blue, Meadow, Salamander, Evergreen, Deep Dark Green and Deep Dark Brown. Given how similar the dark greens are, it’s remarkable how different DDG is to Evergreen and Salamander.
The whole lot in a scan:
Top Row: DD Blue, Green, Brown, Purple, Red and Orange, plus Red Dragon, Oxblood, Ancient Copper and Sunset
Bottom Row: Grey, Graphite, Salamander, Evergreen, Meadow, China Blue, Eclipse (upside down), Imperial Blue, Hope Pink, Amber
Update — alternative scan: