French Government Printer, Multicoloured Engraved Stamps  

 

Hello Florian

What do I think ? I am a little angry.
In the past, before 2005, cylinder (virole) was engraved by moletting.
Now printing cylinders are engraved by a diamond needle directed by computer.
Now, engraving is flat, without thickness. It's a pity.

Papy24

Florian , when you say




due the Chambon presses using chromium-plated copper-covered intaglio impression cylinders.

Do you mean that the fine, soft lines are not possible on
chromium-plated steel intaglio impression cylinders?

I wonder if the Austrian State Printer used similar
copper coated cylinders into the fifties?

I know they had copper hand presses right up to WWII
which printed some of the engraved issues of the
Generalgouvernement.
Possibly the RM values of the 1945 Coat of Arms where also
printed on copper plates.

lithograving - In his description of how stamps are printed on the WIFAG presses, Mr. Vondrich says that the lines of the engraving have to be sharp enough for them to be 'transfer-rollable' but they cannot be too fine nor, on the other hand, too bold. Lines that are too fine get broken in 'transfer-rolling' while those that are too bold either fail to be picked up from the die by the transfer roll due to insufficient pressure or while being forced into the printing cylinder (or plate) the surrounding finer and shallower lines do not get 'transfer-rolled'.

If I am not mistaken, printing cylinders covered with a layer of soft copper might facilitate the 'transfer-rolling' even of very fine lines. By the way, see also the note "The printing cylinder is steel covered with a thin layer of copper to insure a good impression." in http://norbyhus.dk/chuckm.html

The Austrian technique avoided 'transfer-rolling' in favour of electrotyping making it possible for all of the finest lines to appear safely.

Florian, after reading what you mentioned about 'transfer-rolling'
and the quote in the link
The hardened plate then has its image transferred to a soft steel transfer roller called a molette
I remembered this article from the Jan 1989 Danish Post PFC journal.
It shows some of the process rather well I think.
Like the old saying " One picture is worth a 1000 words"











This was probably the M3 Goebel press which Danish Post Printing Works
had been using since 1968 capable of printing up to 3 colours
steel engraving and later modified for up to 6 colours

I found this site recently which has a lot of in depth info regarding the production methods of French stamps.

http://www.timbres-barres-phosphorescentes.fr/

It is in French, click on 'Plan detaille' for the index.

Hello,

I agree, this site is excellent and the webmaster is a friend of mine. I had helped him for some detail.

Papy24

While on Victor Manta's http://www.artonstamps.org/art-on-stamps-1.htm
besides Czechoslovakia, do not forget his overview treat on engraved
France
Art Series
Gauguin - Nafea