The principle of R.G.R. Presses

A High output rotary press (R.G.R. press) is a 4-colour intaglio press which uses the same drying and tracking principle than TD6 presses. The R.G.R.-1 press (High output rotary press number one), called by its manufacturer “Roto Color Stamp”, was ordered in 1970 at the German firm Koenig and Bauer AG and was delivered in 1973 to the I.T.V.F. in Périgueux. For each cylinder turn, this press prints four double sheets of 100 stamps (that is to say 800 stamps per turn) with white margins to separate them. It should be noted that the form cylinder, called sleeve (“virole” in French), is a single steel block covered with 0,4 mm of electrochemically deposited copper.

Here is a simplified scheme of the R.G.R.-1 press:
 

basic diagram of a R.G.R. press

The R.G.R.-1 press is equipped with:

• A double reel of paper allowing a fast change of reel at reduced speed and without having to stop the machine. A paper tray made up of steel rollers positioned downstream to the reels of paper allows to ensure the continuity of the paper supply during the splicing of a paper reel to another one;

• A line-engraving element, with a form cylinder with a circumference of 1.147 m and a width of one double sheet and a plastic wiping roller using an alkaline solution;

• An infrared drying system;

• A flexographic element for phosphor bands printing ( flexography is a printing process similar to typography, which uses a soft printing form, the cliché, made of rubber at the beginning, then of photo-polymer from 1970s);

• An ORMAG’s type rotary perforation system. This system is composed by two cylinders with the same circumference and the same width than the form cylinder (that is to say four sheets for a turn and two sheets in width), one of which is provided with 27192 pins and the another one with as many corresponding holes. The male cylinder engages in the female cylinder and the strip of paper, in passing between the two cylinders, is punched.
   

  

  detail of the pins of an ORMAG perforating device (Source : Copyright ITVF)

   

To facilitate the correspondence pins/holes, 2 to 4 pins and 2 to 4 additional holes are set up;

• Tracking devices controlled by photocells.

The printing of R.G.R. sheets

A R.G.R. press prints top-down four doubles-sheets (called twin sheets) per turn of the copper-coated printing cylinder. Left sheets are called “nappe” 1 and right ones “nappe” 2. Sheets are numbered from 00001 to 00000 (= 100 000 ). Twin sheets have the same control number, followed by the figure 1 for the left sheet and by the figure 2 for the right sheet.

Only one electronic mark (RE) per sleeve is printed. For the tests of the stamp 0,50F Marianne de Béquet, this RE is located after the 10^th stamp of a sheet of “nappe” 1 (thus with the frequency of one sheet in four). It can be noted that from the beginning of the commercial production, the RE will be located in the left margin at the level of the 1^st stamp of one sheet in four having the index 2.

Here is the printing scheme of sheets on a R.G.R. press:
 

printing scheme for sheets on a R.G.R. press

An R.G.R. sheet is 285 mm high and 232 mm wide. The side margins are white and non-perforated, the high and low margins white and vertically perforated. The control number is under the stamp locations 92, 93 and 94, the press code R.G.R.-1 under the stamp location 96 and the date under the stamp locations 99 and 100.

R.G.R. tests of the stamp 0,50F Marianne de Béquet

Before being able to produce marketable stamps with the R.G.R.-1 press, numerous tests were necessary. To date, only tests with the stamp 0,50F Marianne de Béquet are known:

Uninked tests

perforated

• on 26.02.74
   

  

  perforated plate block of an uninked R.G.R. test

   

non-perforated

• from 25 to 27.02.74.

Here is a plate block of one of these printings; it should be noted that it comes from a sheet of “nappe” 1 and that the date of the printing day is not visible.
 

non-perforated plate block of an uninked R.G.R. test

Inked tests without phosphor bands

• 26 and 27.02.74

Known printings are mainly perforated; however, a double inked and perforated sheet is known on 27.02.74.
 

half sheet of an inked and non-perforated R.G.R. test

It can be seen that printer’s markings are printed on the stamps and that the three markings are not aligned.

Tests with only phosphor bands printing

• on 11.3.74;

Non-perforated inked tests with 3 type A phosphor bands

• on 18.03.74.

Only three non guillotined double sheets are known for these tests, among which the following one:
 

double sheet of an inked R.G.R. test with phosphor bands

Here is part of the above double sheet viewed under UV light:
 

photo under UV light of the previous double sheet

This double sheet shows a lack of synchronization between the printing of stamps and that of phosphor bands, which produces stamps with 2 or 3 phosphor bands and a vertical offset of the phosphor bands.

If we zoom on part of the double sheet under UV light, we may notice that phosphor bands are fuzzy and inhomogeneous:
 

magnification of the photo under UV light of the double R.G.R. test sheet

These defects will become more pronounced throughout the run (cf. the R.G.R. sheet shown page 60 of the book “Marianne de Béquet, témoin de son temps” by J. RENARD), because there is incompatibility between the ink for stamps and that for phosphor bands. This will make printed sheets unusable.

On the known test sheets, it can be noted that all the sheets of “nappe” 2 are numbered, but only one out of two for the sheets of “nappe” 1: odd numbered sheets are not numbered. But numbering allows to count sheets. Because of the absence of numbering, it would be necessary to throw either out one out of two sheets or all “nappe” 1 sheets (and this manually), which would be too expensive.

The two problems noted above not having been solved before the date of postal rate change on 16.09.74, no 0,50F Marianne de Béquet sheet printed on the R.G.R.-1 press will be sold. The 1^st sold printing will be the 0,80F red Marianne de Béquet on 25.07.75, with C type phosphor bands.

It can be noted that the main problem for printing on the R.G.R. press was the overprint of phosphor ink on the stamp image. This will lead to a change of the size of the Marianne’s effigy, which will go from 17 mm width to 15 mm to allow the printing of phosphor bands directly on the paper of the stamp. This change will become operational with the stamp “Sabine de Gandon”.