Isograph Technical Pen, 0.25 mm

Pen consistently lays down a fine line. I’m using the Rotring ink and the pen has not clogged even when sitting unused for several weeks. I use it for sketching and watercolor highlights. It’s great for small drawings where I need detail with a very fine point. As others have said, this is a technical pen, and must be used fairly perpendicular to the paper. Once you grow used to that, it’s great.

I used the Koh-i-noor brand for years, and went back to dip pens because they were so unreliable. The Alvin pens are superior, but very hard to find. Microns, in my experience, are ridiculously expensive, and often run out of ink during the first or second use. People probably use them because the other brand of tech pen popular in the U.S. is way too much trouble. I tried one of these, and now have four. They are easy to use, clean, and, as long as Rotring ink is used, they do not clog, even after several days of lying unused. The Koh-i-noor pens seemed to clog if I looked at them too hard. I have the .2, .25, .3, and .4. I DO NOT recommend using regular ink, even good ink, that is not designed for these pens. My favorite black ink is Dr. Ph. Martin's Bombay ink, but I DO NOT use it in these pens. It WILL clog them, even though the label indicates it can be used in technical pens. Other than being held hostage by the Rotring ink, I cannot think of a downside to using these instruments. Great product.

These pen make an excellent fine line for pen and ink work. They are durable, being refillable cuts cost and they rarely if ever clog.

So far, so good, hasn't clogged and doesn't get snagged on watercolor paper, smooth lines

Very fine line, very easy to refill. Took just a second.

25 mm was a dud. Stopped work by within the matter of a couple of weeks. I even cleaned the nib and it still won’t function.

Rotring pens are AMAZING. I'm actually replacing all of my Koh-i-noor technical pens to Rotring after my first purchase of a .10 mm a few months ago. The ink flow is SO smooth, no "skips" as you're drawing, and you don't have to fight it after you get the initial ink flow (which, getting the ink flowing is super simple too!). These pens are amazing, and are a must have for any illustrator, artist, graphic designer, etc. who heavily uses technical pens in their work.

Precisely what we needed.

As expected from Rotring, perfect engineering

Je les utilise depuis des décennies, super qualité. Par contre utilisez l'encre Staedler car l'encre est plus fluide que la rotring tout en étant indélébile

Super snabb leverans

This pen is good for Calligraphy, Architectural designs, Cartoons or Designs Pros: No Ink blotting even when making very close lines together The flow is good Built quality is good. Re-fillable The cap is also screw based. Cons: Costly Ink from Rotring is costly. (I am using currently Parker Quink = Rs 50 only) Delicate Nib Old style design. Boring looks One need to be very cautious while lending this to someone who is not good with pens Overall, this is a superb pen. Parker Quink can be used as well for a smooth and smudge free writing. Rotring Ink would be best (but not easily available in stationary shops). PS: .25 Nib is very small for regular writers. They should go with Min .35 or above.

These are much better at keeping the ink from drying out than other brands that I've tried. I have 2 sizes now and probably will order another one.