I’ve always loved using drawing pens, although I would often use them for my tiny writing, rather than technical design or drafting which is what they are designed for.

In an earlier post (Some ink is not permanent), I compared the Staedtler pigment liner 0.05 with the Sakura Pigma Micron. The Staedtler is the one I’ve used for years; larger newsagents/stationers shops in the UK have these.

The Micron 005 is typical: the tip is made of fibre encased in a metal tube. It’s easily bent by applying too much pressure. How I perceive the firmness of the tip affects my writing. If I feel it “give” then I’ll lessen the pressure on the pen a bit.
Actually in the first photo there are two metal-tipped pens: the brown 0.4 is a Pilot Hi-Tec and the orange 0.38 is a Muji. Obviously one can write more confidently with a metal tip, but the line is thicker and the ink is not usually archival. It’s this permanence which has drawn me to drawing pens. Since I’m taking notebooks out and about they run the risk of getting soaked, and — without wishing to repeat too much of my earlier post — I have to tell you that gel ink completely leaches away when water percolates through the paper.

There are many 0.05 drawing pens from lots of manufacturers. The actual width of the tip is about 0.4 mm just below the rounded end, and the line they leave is usually around 0.2 mm in width. I may be splitting hairs (average human hair=0.001 mm) but I think most of the manufacturers label their smallest width as 0.05, or “005” to indicate it is smaller than the 01.

I got about a dozen to test and thought the best way to compare them would be to see how many words I could fit into a square inch. Look, this is just the way my mind works! First of all, my choice of paper was bad. Whitelines paper is great in many ways, but wet inks will spread a bit. I also thought my #inchquote hashtag would rule the interwebs.
Still, this did show a shortcoming of the purple Pilot 005: only 36 words per square inch as the Uni Pin takes an early lead with 68. (I had five of the Pilot pens: they all performed the same. Clearly I needed to try them on a better, smoother, less porous paper.)

We have a new leader: the tiny writing of the Copic Multiliner sepia 0.05. The 10p coin shown for scale is about the same size as a US quarter, because I couldn’t find an inchworm.

The sepia Copic pen retained the crown. This is getting far too exciting so here is the rundown. All these pens contain waterproof and lightfast/fade-proof pigment ink, with a plastic barrel unless stated, and they are all pretty cheap when you consider that your journals made with these could last for ever.

Artline Drawing System 0.05. £2.85. Water-based ink. Acid and Xylene-free. Comfortable pen with a firm polyacetal tip. The only drawback is that the cap posts on a nubbin 2 mm long. 9/10
Copic Multiliner Sepia 0.05. £2.86. Marker-proof ink. The grip is a great shape with no ridges, and I found the sepia ink actually wrote the smallest of all the pens on test. There is a glitter effect on the barrel and cap. Also available in black, if you find this sepia too light. 10/10
Copic Multiliner SP 0.05. £5.00. Marker-proof ink. Aluminium-barrelled pen, but only 12 g. Nice fine line. Refills and replacement nibs available. The black is a bit grey. (There is also a 0.03 width but this is out of stock everywhere.) 9/10
Edding 1880 drawliner 0.05. £1.60. The fibre tip puts down a consistent, very black line, but it’s scratchy. It will probably wear down quickly. Nice price. 7/10
Faber-Castell Ecco Pigment 0.1. £2.50. This oddly shaped pen writes as fine a line with its fibre tip as some of the nominally finer pens here, but there is a big ridge in the “ergonomic grip zone” unless you have a really low grip. The ink pad inside rattles around. 6/10
Nikko Technical Finepoint System 0.05. £9.99 for 12. Water-soluble and presumably not archival ink. Undistinguished-looking black and white pen with a nice plastic tip. (NB there is also a permanent version of this pen for writing on film, plastic etc. that has a grey barrel and blue cap and writes a much thicker line.) 5/10

Ohto Graphic Liner 0.05. £1.75. Needlepoint (tiny rollerball) metal-tipped pen which writes a slightly thicker line than the other pens here, but still has the pigmented ink. The answer to a Field Notes notebook users dreams? Maybe not because the ink is quite wet and may bleed. Black with orange lines on the barrel. 8/10
Pilot Drawing Pen 005. £2.99. Writes a thick line of wet ink that bleeds more than the Ohto. Nice purple pen with funky grey squares that writes more like a 0.1. I imported mine from Japan: there is now a UK version with white blobs instead of grey squares which I shall have to try, but this Japanese one is not as good as the old Pilot DR pen. 5/10
Sakura Pigma Micron 005. £2.21. Archival ink. Acid-free. The original pen of this type. Lightweight and controllable pen that lays a dark black line. The tip does wear down to nothing before the ink runs out, though. 14 colours – imagine the Zentangles. 9/10
Staedtler (308) pigment liner 005. £2.40. Another classic pen. Good to write with. Firm tip. I find the ink runs out before the plastic tip wears down! Indelible (in accordance with ISO 14145-2) – resists highlighting. 9/10
Uni Pin Fine Line 0.05. £1.74. As good as the Staedtler and writes an even finer line. there’s a funky window in the cap so you can see the polyacetal tip. 10/10
Zig Millennium 005. £1.80. Acid-free ink. 8 colours. The grip section is relatively thick which I find uncomfortable. Nearly as heavy as the metal Copic SP at 11 g. (The rest of the pens are around 8 g.) 7/10
The pens, tested on Rhodia paper:
Other pens to consider: Kuretake Zig Mangaka Drawing Pen 01, Edding 1800 Profipen, Derwent Graphik Line Maker Drawing Pen Black, Aristo GeoCollege Pigment Liner Drawing Pen, Marvy Le Pen Technical Drawing Pen – 0.03 mm – Black etc…
In the UK you can find these pens at Tiger Pens, Cult Pens: Drawing Pens and Copic who sell other brands, not just Copic.
Cult Pens have a Guide to Technical Drawing Pens; while JetPens in the US have a Guide to Drawing Pens and a Guide to Technical Pens.