I’m obsessed with ISO 12757-1

A few years ago, when we still lived in the center of Tokyo, I made a few cool art supplies stores the goals of my walks. Once or twice a week, I would stroll to Ginza or Nihonbashi and visit stores there or along the Sumida river to the Kakimori. I would just browse, test some cool pens, and walk back.

It’s in Kakimori, though, where I found the Internoitaliano Neri ballpoint pen – a very simple tool inspired by the design of old compasses – just a metal stick with a hole for the refill and a thumb screw to hold it down. It instantly got my attention because this construction gives it two very intriguing features:

• When the refill is clamped down with the thumb screw, it will not budge. This construction removes my main pet peeve about using ballpoint pens for drawing – how loose and rattly the tip usually is. Here there are no springs or ratcheting mechanisms. Everything is held in place perfectly!
• It’s easy and fast to change the refill for a different one – loosen the screw, and the refill falls right out.

When I bought the pen, it had a Schmidt 635 M in it – a very popular, oil-based, waterproof workhorse of a refill. I was instantly drawn to it because it allowed me to sketch just like with a pencil. It responds beautifully to pressure allowing for very wide, dark lines and delicate shading too. The ink flow doesn’t “stall” at all but is not too fast either – it does not produce huge dollops of ink when drawing curves which is a big problem with some ballpoint refills. (apparently, in Korea, they call these ink-burps fittingly “ink poop,” at least according to the late Master Kim Jung Gi.)

I used this pen for a lot of rough brainstorming and also with watercolors for more involved illustrations, and I got my money’s worth even though it was over-expensive for a ballpoint. This pen got me back to using (and liking) ballpoint pens for creative work; I’m grateful for that.

But the fun does not end here!

The Schmidt 365 M is a D1 type refill – an ISO 12757-1 international standard. This means that any refill 67mm in length and 2.3mm in diameter will work. A quick search for D1 type refills gave me this comprehensive list of many makes and variations: Ultimate Guide to D1 Refills

Yes, some of these are overpriced or just not easily available, but most can be bought for around 0.8 to 5USD a piece. Especially in Japan, where multi-refill pens are very popular, the D1 standard is widely adopted: a quick walk to a neighboring office supplies store provided more than ten types of refills to test and play with!

From these, a few turned out to be disappointing, with a lot of blotchy dollops of ink coming out at most random times, being scratchy, or not performing well when used with very light pressure or for fast strokes (cross-hatching).
But most worked very well for sketching and were also nicely waterproof and so usable in combination with watercolors! (Of course, I have completely no idea how lightfast and long-lasting the inks or dyes in these refills are, so be careful when doing any final work!)

From all the refills I bought and tested so far, I chose six or so that give me different line types, and to have them in a more manageable shape, I made a small fabric holster the size of a business card. It fits nicely in the cover or back pocket of my sketchbook. It’s like having six different pens in the size and weight of only one! Here is my current list:

OHTO R-4C5NP – good for thin lines
STAEDTLER 92RE
SCHMIDT 635 M – I still like it!
MONTBLANC Ballpoint Pen Small Mystery Black refill – very smooth!
LAMY M21 – recently, I use this one most
PILOT LHRF-20C4 (Hi-tec c) – great but not waterproof
PILOT BRFS-10F – good for writing
LAMY M55 – orange highlighter refill

I have been sketching a lot with the Neri pen, having fun switching the refills according to my needs and current mood. It might be fun to look for a three-color pen with the least pen tip wobble to try to fill it with three different black refills for the ultimate ballpoint pen sketching experience. For now, I’m grateful for international standards, like the D1 refill, which allow us to get even more joy from our tools.