Help Identifying This German Stamp Of 1924

This appears to be MiNr 357X. But there is a somewhat rarer variant printed on Faserpapier (what Scott calls "Granite paper"). I can see at least one colored thread. Would that be enough to call this MiNr 357Xx?

Maybe I should have worded my question differently. Is this stamp on "granite" paper (i.e., Faserpapier)?

Be patient, NSK or one of the other European stamp experts will take a look and provide you with their opinion. They might all be watching the Olympics this weekend.

Emaxim, why not contacting PostmasterGS on this community ?


Peter

Didn't realize I cd contact someone directly. How is that done?

And yeah, I forgot about the Olympics.

Those issues aren't particularly rare, so it's certainly within the realm of possibility. I would expect to see more threads than that, though.

Yes, that's why I'm hesitating. One thread didn't seem sufficient. I'll call it Faserpapier for now, but with a question mark. Thanks for your opinion.

Actually, spending the weekend abroad.

Hopefully the Olympics pass quickly and there will be something else on TV but these infernal games. The only thing I would be interested in watching is the hockey.

Interesting question.
I checked my stamps from this series and unfortunately I did not find this deviation from the normal paper.
The examples found (certified) on the net do not have a sufficient resolution to observe these textile fibers.
The terms found in the Michel catalog:
"faserpapier" = ? fiber silk paper
"gafasertes Papier" = granite paper
they did not clarify the difference between them.
Does "Faserpapier" have fibers of different colors? I could not find the answer.
@EMaxim, I advise you to look carefully for other traces of fibers.
Normally you should also find it on the face of the stamp (they can be much smaller than your example and - if they are colored - even harder to notice)
An example with a stamp on "gefasertes Papier" where the fibers can also be observed on the face of the stamp:



There aren't many fibers, but just one as you found, I don't think it's enough.

It looks like a fiber adhered to the stamp.

Here is an example on ebay, claiming to be expertised. The problem is that an expertiser's mark does not say what it has been expertised as.
https://www.ebay.at/itm/255374775980

@NSK, Nice example found.
I saw at least 5-6 fibers on the front and back of the stamp.
The letters "Xx" clearly indicate what it is certified for:

Now I see.

Thank you Cupram, very helpful. I'll examine more closely, both back and front. What NSK has said about a single fiber adhering to the stamp has been my concern as well. As PostmasterGS said, and as Cupram shows, we normally see many, or at least several fibers.

As for terminology: If "Faser" means "thread," then "Faserpapier" wd be "thread-paper" (or "paper with threads") and "gefasertes Papier" wd be "threaded paper." I've always assumed that they're synonyms, indicating no difference at all. If someone knows better, I'd welcome the chance to learn.

Here are some close-ups, taken with a digital microscope. See what you think. Are there enough threads to call this Faserpapier? For if there is only the one large one, I'll tend to agree with Cupram that that's not sufficient.

I, still, think that big one visible in the first post is 'foreign matter.' But it does look like there are fibres visible in the stamp paper. However, are they the silk fibres you would be looking for?

Blowing up the picture may also result in false positives at some stage.

The large fiber is certainly anomalous. And there aren't many of the smaller ones. None at all on the margins of the face.
And yes, at some point (even here) enlargement confuses things by showing the normal fibers of quite ordinary paper.