Berlin/Brandenburg Perforation Question

I hope somebody can help me with this question:
What is the difference between "SERRATED ROULETTE" and "ZIG-ZAG ROULETTE"?
Description in Michele Specialized catalog is very cryptic and I cannot find any images with clear visible difference between AA and B types.
Picture shows obvious perforation difference between stamps 1 AA and 1 AB, but difference between 1 AB and 1 B is complete mystery for me.

At the moment I cannot show you an example.

But if you have the Michel specialized? You should find a little drawing showing the differene between the 2.

Sagezahn is more or less 2 diagonal lines. zickzack appears to also have al little roof
.

Technically, Johan is correct but I have never been able to discern the difference between those two roulettes myself. However, you can tell the stamps apart by the orientation of the gum ripples, or lack of them (even on used or stamps with no gum). Here is a chart I put together a few years ago. (If there are any errors in the chart they are my own). It covers the entire set and all the varieties.

@Igopp

Your stamp is A and B

A perf 14

B perf 13½ the stamp has a ZigZag like perforation, the paper has a horizonal structur same with mouthglue as it tends to follow the paperstuctur

AB perf 13½
only 2 values has the significant perforation the 5 pfg. and the 12 pfg.
The paper is smooth or Vertical riflet paper and mouthglue the perforation is like sawtooth.

I can't show you one as they are relative hard to get. As you can see at the drawing the perforation is more pointy( I think is callede)

I have an example of AB type roulette (line cuts)



The B-type roulette has the Z-shaped cuts (see the little red lines I added)
Type B roulette stamps only have gum with horizontal lines.

Thanks everybody!
I am with Germania: I have never been able to discern the difference between those two roulettes myself.
I do have "Michele Specialized" and I looked at that small perforation picture many times. I have huge inventory of those stamps, but all of roulette perforations look the same for me. I also checked out many pictures on ebay. Some of them apparently show stamps type B, but perforation looks the same.
I also could not find any Horizontal gum orientation. It is quite strange considering relatively low price of stamps with Zig-Zag roulette perforation.
Cupram - thanks for your picture. I think your stamp is type A with z-gum. It would be interesting to look at gum of B type stamp.

I found this image:
Michel #2 Ba; Zig-Zag roulette perforation (there is no serrated roulette perforation for #2)
As you can see, there is no visible difference between perforation lines (I cannot find any Z-shaped cuts).
So it looks like the only objective difference between types B and AB is the gum (horizontally ribbed gum for type B).

I don't have B roulette stamps.
These were issued last on December 6, 1945.
My hypothesis is that due to the difficulty of detaching the stamps from the sheet, they changed the thickness of the knives and their inclination so that the distance D1 is smaller.
I don't know where the name zig-zag roulette (B) came from, but it seems to cause confusion.
I compared your picture with type AB roulette.

Cupram - the Zig-Zag definition is coming from Michel Specialized English Edition. I have attached definitions from both German and English editions for comparison.
I also found some "B" stamps in my inventory and it is very clear that perforation of types "B" and "AB" is very similar (see scan of 4 "B" stamps).
So the only objective criteria is the back side - gum type. On the last photo you can see horizontal gum orientation on "B" stamp.

jgopp - beautiful examples of stamps.
I have the specialized Michel catalog and my question was about whether the information in the catalog is wrong (I also found other glaring mistakes)
I will try to find an answer on a German website.

I found amazing discussion about Berlin & Brandenburg series here:
https://www.stampboards.com/viewtop...ntl#p6092384

Author came up to the same conclusion:
It is very difficult to see any difference between perforations of stamps "AB" and "B". The horizontal gum structure is the only way to determine "B" stamps.