D1 ≠ D1 2


Not everyone shares this opinion, not even everyone in my household, but I think gel refills are so much nicer than ballpoint refills. My holbein x Rotring 600 3 in 1 came with ballpoint refills, so it was a prime candidate for an upgrade: replacing the ballpoint refills with gel or hybrid refills. I had the idea after A.J. talked about the D1 refills in a comment on my video about this pen.

I started by consulting Ana’s refill guide to look for some nice refills.

It didn’t take long to pick some cool stuff for my order, not only refills, also a new pen (the Jetstream Edge in white). To get free postage with my order I also picked a few more refills with the intention of improving my wife’s Lamy 2000 multipen (the original Lamy ballpoint refills often skip when you start writing).

The two patients of this operation: Lamy 2000 and holbein x Rotring 600 3 in 1

What did I order? Jetstream refills, I like them based on my positive experience with them from the Hobonichi pens and from my Jetstream 4 in 1. I also got some Zebra refills. I haven’t used them myself but bought them before to go with a pen I gave someone as a gift.

When trying to fit the Zebra refills into the Lamy 2000 there was big disappointment. They didn’t fit. A quick look at the end revealed that the Lamy refills are slightly slimmer. Maybe D1 isn’t quite as standardised as I thought. I have to admit though that I don’t have much D1 experience as I generally prefer pencils and fountain pens.

A quick check with the callipers revealed that there are minute differences in the diameter. The Lamy M21 diameter is 2.32 mm, the Zebra JSB 0.5 diameter is 2.36 mm. 0.04 mm (0.0016 inches) difference. I also measured the Uni SXR-200-07 which turned out to have a diameter of 2.33 mm. Even though the Zebra didn’t fit the Lamy 2000 I managed to squeeze it into the Rotring 600. That left me with the uni for the Lamy 2000. The refill is only 0.01 mm wider but that was enough the turn a relaxing Sunday drive refill with butterflies (and the Loving You song in the background) into a heavy metal squeeze fest (with some Rammstein song playing from a broken stereo) with thoughts in my head that the Lamy 2000 will crumble under all the pressure. In the end it did, luckily, work. According to my own refill guide the D1 diameter is 2.35 mm. Who would have thought a fraction of a millimetre makes such a difference…

Since I talked about Holbein: Radio 4’s book of the week happens to be about him: The King’s Painter: The Life and Times and Hans Holbein.


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2 thoughts on “D1 ≠ D1

  • Ana

    I have squeezed the Zebra D-1 gel refills into my Lamy 2000 multipen. In fact, I’ve never used anything but the Zebra refills in it. I’m sorry they didn’t work for you.

  • memm Post author

    I was really scared I’d break it. I wonder whether either your Lamy has slightly bigger diameter or your Zebras had a smaller one. Since Lamy is updating the 2000 fountain pen every now and then (feed etc) my guess would be that your 2000 multiplem is slightly different.