"Stones" For Old Swiss Stamps

The old Swiss stamps type Rayon I , II, III are numbered according to standard catalogues ( Michel, Zumstein, Scott…).
But in addition, there are additional values for classification by "stone".
Does somebody know where I can find the detail of the stones with the aim to determinate by myself the type of stone for each stamp I have.

Thank you

Priatel, could you tell us where you found this reference to "Stone(s)"/

Peter

This is in Zumstein, Michel or SBK catalogues.
The stones ( stein) are from the stones for printing the stamps.
And they are classified A, B, C.....
Each stamp printed with a specific stone has a specific additionnalmvalue.
And I would to know where I can find documentation about the catalogue of the stones.

Check out this site:

http://www.swiss-philately.co.uk/st...federal.html

The types are depicted.

Please let us know how it goes.

eta: I've posted this before, but it is sort of relevant here. Sismondo gave this one a cert as Type 39 of 40:

@Cjd
Thank you, it'ws exactly what I am looking for !
It is very helpful for me.
I can start searching for additionnal littérature and in particular for the Zumstein 124 !

But it remains a problem !

The tables shown on the site you gave the address are the distribution of the types of stamps ON the stone.
But the stones themselves, how to make the difference between them?
They are called "stone A1, A2, A3, B1,...."
And the additionnal value of the stamp is 100% dependent from which stone it was printed.

Then, the question: Where can I understand how to differenciate the stones from the image of a stamp ?

Thank you again for helping me !