Certainly not a fine tip. Produces a thick line. If I had to guess, I'd say somewhere in the 0.5-0.7mm range, but probably closer to 0.7mm. This might be remedied by writing faster as it gives less time for the ink to flow to one spot.
The idea of a pen made solely out of glass is a little foreign to me. We're brought up to believe (that is, ingrained in our heads) that a pen is made from plastic and contains a cartridge of ink within its body.
The style of writing harkens back to simpler times; simpler in many respects and perhaps pens are symbolic of that. We live in a time where the more complex the devices and the more technology it has, the better. We assume it will perform because of the complexity and amount of technology. If it doesn't have more than 10 moving parts, it must not perform well, because, heck, where is the technology? We want something to brush our hair, order shoes online, drive our cars, all while cooking our breakfast.
The glass pen is a refreshing reprieve from this madness. It's really as simple as you can get. No moving parts, no flashing lights, no fancy touch screens. Just pen and ink.
Where the pen really shines is in showcasing the idiosyncracies of the ink itself, instead of the pen's characteristics overshadowing the writing experience. To really get the full effect, I think it would be best to use multiple inks with the glass pen. Ink can be washed off very easily from the tip of the glass pen. This allows use of multiple types of inks and allows for direct comparisons of the inks side-by-side. For instance, my girlfriend and I have been experimenting with the Noodler's Ink Mixing Kit and trying to come up with some cool, homemade colors. (I'll most definitely have a post about that sometime soon.) We've definitely noticed that when the ink is in the vial, it can look drastically different than when the ink meets the paper. The glass pen is the perfect tool in seeing how the ink flows and how it looks on paper. If we want to add a few drops of a certain color, the ink on the glass pen is easily rinsed off and the newly mixed ink freshly applied.
In short, the glass pen is the most intimate interaction between writer, pen, ink, and pad. In my opinion, writing in its purest, original form.
Of course, it's not the most ideal pen for quick note taking in class, for example. But, nonetheless, even if you don't use it that often, it's a great piece of artwork.
The box that the pen comes in, however, hardly does the workmanship justice. I received a pen stand that was custom made for the glass pens courtesy of Zero_dgz from the Jetpens.com forums. This pen stand is the absolute perfect way to showcase the glass pen. The stand is displayed on my workspace and I've certainly gotten a few interesting looks and inquiries about the glass pen from passersby. Zero_dgz does great work, thank you!!