A nice picture of "iridium" tip with an incredible number of features:
1) Notice the porosity on the tip surface: two kinds a large one (spherical) of the order of 20 microns (1/3 of a human hair diameter) and smaller one about 1 micron.
2) line marks: in the transverse on the top and at 45 close to the spherical pore. Could be either from grinding or from writing.
3) Is this the "baby bottom" effect?
4) Notice the rough surface in the side wall of the slit - from the cutting wheel.
5) the particle on the surface (lower and left from the big pore) is probably dust.

This is a Warranted #8 14K nib. Photograph courtesy of my freshman students who took a project with me on "How did it break and why?" Unfortunately their element detection analysis was not correct, so I can not tell you whether the tip is from iridium. I will post other photos from this project soon.

Wow, that is so very interesting! Thanks for sharing this with us Antoniosz.

Bryan

Was this a fine nib. It would appear so from the flat paddle shape.

It looks like a fine - I can not tell because the other tip is broken.

AZ

Looks like the tine of an arabic nib to me. It seems so high compared to its width...

Any ideas, Antonios?

TIA, warm regards, Wim

It is a regular fine. Remember that it is a single tine. You put two of them and it does not look strange any more. I got other very interesting pictures (3D, needs 3D glasses) of the whole thing which I hope to post sometime tomorrow.


AZ

Interesting. Thanks for sharing Antonios. The curve towards what was the other tine tip does look like a baby bottom issue indeed.

Do you have any pic of higher quality vintage tipping ? It would be interesting to compare the porosity.

Did you have "baby bottom" problems with it? I'm not convinced this pen would be a skipper. The writing surface should be between the dust bit and the large pore. That area doesn't look at all like it would be a skipping problem. The fact that it's rounded up at the top shouldn't make a difference.

Denis, no I do not have other photos The instrument is overbooked. I can only sneak couple couple of sessions per year in such projects.


Kendal, as I said before, this was an already broken nib. I never had a chance to try it. It appears from the picture that there is a curvatureall all along at the inner edge of the tip. I am not sure if this is enough to cause problems.

... but you need the tipping on both tines to make contact with the paper right at the slit for capilarity to work. I think it's hard to tell how much of an issue this very curve would be, considering the scale of the picture.

Now that I look closely though, the edge on the slit side seems well polished, which seems to indicate that there was good contact with paper at that point. Say Mr. A.Z., was this a flexible nib ?

The 45 degree marks seem to be all in the contact area (which length I define by the smoothed portion of the slit edge). That would indicate writing origin, more than grinding. May be residues of some sort on the paper. What is that powder used for blotting called ? Would that be tough enough to mark a tip ?

Denis,

It is not possible that the curvature in the slit corner came from flexing.
That would only occur at the contact point. If you look carefully (Kendal noticed it first) there is a area (which corresponds to about 45 degrees of holding angle) that is smoother than the rest of the tip. This is where contact with paper occured.
But hte curvature is pronounced all along the tip edge.
It seems that it came from polishing/shaping of the original tip.

Hi Antonios,

I did not think that the inward curve was caused by flex or anything (I think it's a manufacture issue). There is a smoothed edge that tells you precisely (well sort of...) where the contact area is. I'll make a little drawing on your pic later today.

I was asking about flex because of the smoothed edge, which seemd to be possible only if the slit opens enough.

Denis.

Here it is. I marked the very edge of the slit that is smoother than the rest. I think it defines the length of the contact surface pretty well.

It the picture is not inverted, I would guess that the writer was turning his pen counterclockwise, smoothing the slit edge on the right tine, and putting more strain on the left tine (rough diagram by the pic).

My guess would be that the baby bottom comes from manufacture (factory initial grinding ?). I don't think regrinding of nibs was common when FPs were in widespread use. I have a feeling that it is more a modern user practice. What do you think ?

Files recovered!!!!! Some details of the previous picture.
No it is not a landscape from the moon but from the tip of a nib.