Diamine Ruby fountain pen ink bottle

Ink of the Week – Diamine Ruby

John BosleyFountain Pen Ink 6 Comments

This week we’re going to take a look at Diamine Ruby. I bought this ink years ago when I came across a deal on Diamine inks. I don’t think I had a particular reason for choosing it other than I needed to purchase 4 bottles of ink. In the years since I acquired it, I have hardly used it at all. I wonder why that is? Let’s take a look and see what Diamine Ruby is all about.

Diamine Ruby fountain pen ink doodles

Diamine Ruby

To start, let’s take a look at the ink itself. As you would expect from a ruby-colored ink, it is red. It is actually a fairly intense red color, almost what I’d consider to be a “pure” red. It’s really quite nice. It doesn’t have a lot of sheen or shading, but does have a bit of each. The shading really showed up with drier nibs and the sheen showed up with wetter nibs. The sheen isn’t the gold sheen that is typically associated with red ink, but instead is a nice dark edge varnish sheen that looks fantastic.

Diamine Ruby fountain pen ink sheen

This sheen is more of a varnish

Diamine Ruby fountain pen ink sheen

You can see how the writing has a bit of a dark edge to each stroke

When exposed to water, this ink doesn’t have an interesting chromatography. It just gets a little lighter. Once dry, it is not very waterproof. You may be able to read what was written if an entire page got wet, but I wouldn’t count on it.

Diamine Ruby fountain pen ink chromatography

This ink just gets a bit lighter with water

Diamine Ruby fountain pen ink waterproof

This ink is not very waterproof

Dry time for this ink is fairly quick. It helps that it is not a super-saturated ink, which again is unusual for a red ink. Once dry, it will smear a bit but not very severely. It’s honestly pretty impressive for a red ink, as I feel that most bold reds I’ve used have smeared quite easily.

Diamine Ruby fountain pen ink smudging

This ink has a bit of light smudging once dry.

The Pens I Used

Each week I choose five different pens to fill with the ink I’m testing. My goal is to get a variety of nib sizes and styles, as well as a mix of modern and vintage pens. Here are the pens I chose this week and some writing samples from each:

Diamine Ruby fountain pen ink pens for the week

Here are the pens I used this week (L-R): Jinhao 599, Vintage Pilot, Parker 51, Cross ATX, Lamy Studio

Diamine Ruby fountain pen ink nibs

Here are the nibs for the week (L-R): Jinhao F, Pilot F, Parker M, Cross M, Lamy B

Jinhao 599 – F nib

This combo was probably the least exciting of the week, but it still looked good. The Jinhao nib isn’t wet enough to show off the sheen, but not dry enough to show off the shading. Still, I enjoyed writing and doodling with it.

Diamine Ruby fountain pen ink jinhao

Writing sample with fine Jinhao nib

Pilot (vintage) – F flex nib

This vintage Pilot has a very fine and very wet nib. I love the way the ink looked with this combo! I normally don’t enjoy fine nibs, but really liked writing with this one.

Diamine Ruby fountain pen ink f pilot

Writing sample with F Pilot nib

Parker 51 Demi (vintage) – M nib

This Parker nib is similar to the Jinhao in that it’s not super wet or dry. It was nice to write with, but not very special.

Diamine Ruby fountain pen ink parker 51

Writing sample with M Parker nib

Cross ATX – M nib

Definitely my favorite combo of the week, this Cross nib is nice and wet and made this ink look great. I found myself writing and doodling with it more than any other pen this week.

Diamine Ruby fountain pen ink cross

Writing sample with M Cross nib

Lamy Studio – B nib

I was surprised by this combo. I didn’t think that this Lamy nib was that dry, but it sure felt that way with this ink. Look how much shading it has!

Diamine Ruby fountain pen ink lamy

Writing sample with B Lamy nib


On cheap paper, this ink bled through with all pens, but it wasn’t too extreme. I did see a bit of feathering with the wetter nibs. On fountain-pen-friendly paper, things fared much better. I didn’t see any bleedthrough or feathering with any of the pens. I think this ink should be safe to use on any decent paper.

Diamine Ruby fountain pen ink leuchtturm

Writing sample on Leuchtturm paper

Diamine Ruby fountain pen ink g lalo

Writing sample on G. Lalo Verge de France paper

Diamine Ruby fountain pen ink life noble

Writing sample on Life Noble paper

Cleaning The Ink Out Of Pens

Here’s the true test for any red ink. How easy is it to get out of your pens? Thankfully, not very difficult! Of course, it does take a good amount of flushing before the water runs clear, but residual ink doesn’t remain in the pen like with some red inks. I feel like with other reds, even when the water runs clear, if I let the pen soak a bit with clean water more red always comes out. With this ink that didn’t happen. For the Parker 51 it took quite a while to get all of the ink out (which is common for that pen), so I would avoid using this ink in pens that are typically harder to clean. If you want to speed up the cleaning process, you can always use an ultrasonic cleaner.


After having this bottle of Diamine Ruby for so many years and never really using it, I am pleasantly surprised by how much I enjoyed using it this week. The rich red color accented by a darker sheen really looks great, especially in a wetter nib. In addition to that, it dries fairly quickly and isn’t a smudgy mess once it dries. Unfortunately, I think that I just have to accept the fact that I don’t love using red inks. What I do know is that if I want to use a red, this is probably the one that I’ll reach for.

Diamine Ruby fountain pen ink flex nib

Comments 6

    1. Post
  1. Interesting, John.
    Yes, red is not a favourite with me. I had some years-old Quink red and green, so I mixed them and the result was a lovely brown. Red and blue was another. It made nice colours, but proportions are important.
    I like Diamine inks, but I’ll give this a miss. I wish I could doodle like you. Is it a result of misspent school days?

    1. Post

      Mixing inks definitely takes a bit of practice to get something that looks halfway decent. In my brief time experimenting with it I’ve had more misses than successes.

      I never doodled in school and always took good notes. This is just something more recent as a way to use my pens but not having much to write about. As with anything, it takes a bit of practice and consistency, but try it out and you’ll start to see some improvement!

      1. John, regarding mixing same brand inks. I use a dropper. If 2 drops of green and 1 of red gives me the colour I want then I have the proportions. I might add another red drop. Then I put the mixture in an empty cartridge to see how it looks in use.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.