When Cult Pens and Diamine came out with their first two “Iridescink” shimmering inks together they turned to the fountain pen community to name them, jokingly suggesting Robert and Maureen as possible names. The fountain pen community duly said “challenge accepted” and voted that the inks be called “Robert” and “Maureen”. I thought that this was a charming anecdote until I actually purchased three of the now four Cult Pens/Diamine Iridescink inks and realized that I with names like Robert, Maureen and Christine I would never be able to tell which ink is which.

This, of course, is a minor problem for an otherwise solid addition to the world of fountain pen inks. These inks are super sheening and generally well behaved, with a good solid base colour and an interesting sheen hue on top of it.

Robert, a purple ink with a green sheen (I will forever have to consult a guide when trying to remember which ink is called what), is one of the most attractive inks in the bunch. It features a reddish purple somewhat reminiscent of Diamine Amaranth, and a gorgeous green gold sheen.

On Rhodia paper with a Lamy fine nib you can see the green sheen on almost every downstroke. It’s also well featured in the swap I took in my Col-o-ring.

For the biggest sheen effect, of course there’s nothing like tomoe river paper. Here’s a quick sketch that I did on a Kanso Sasshi tomoe river booklet. As you can see the ink isn’t waterproof or water resistant (not that Cult Pens or Diamine claim that it is), and you can barely see the base colour in most places because of the heavy green sheen.

So why did I say that Diamine Robert is “generally well behaved” and not just “well behaved”? Because if you leave it unused in a pen for a day or two you may find that you need to “prime” the pen for a bit to get it to start to write. Once it gets going the ink flows well, but this is the sort of behaviour that makes me wary of using this ink in vintage pens. Your milage may vary, as ink flow changes with altitude and weather, but for now this gorgeous ink is relegated to “just” my modern pens. That’s more than good enough for me.