PRINCIPAL TYPES OF PRINT
|ENGRAVING or RECESS PRINTING (TAILLE DOUCE)||
|PHOTO ENGRAVING (HELIOGRAVURE)|
In this procedure the engraving furrows printed the color on the paper
while the reliefs caused the white ones; therefore it is the contrary respect
In this method of press it is impossible to obtain a large uniform surface; to obtain it, it is necessary to engrave a very narrow plaiting of thin lines that give the impression of a uniform background, that however are distinguishable easily using a magnifying glass.
Beginning from the engraved and hardened die, it is obtained a transfer spring, that it is hardened itself.
It is used to create, for pressure, the print cylinders (figg. N1, N2), currently called coinages.
This procedure has appeared on March 2, 1939 for the
stamp "Red Cross" n° 422.
The T.D. 3 can print sheets from 10 to 100 stamps, carnets or roulettes.
The print cylinder is in metal; it receives the colors from three inking rolls (figg. N3, N4), (fig. N5), everyone supply with a different color ink.
These inking rolls are made in hard plastic
material; they are hand engraved one for time, in way to have in relief
only the portions destinate to receive a single color to deposit it subsequently
on the metallic print cylinder.
Every inking roll in this way engraved, introduces on the cylinder only one color in T.D. 3. There is not any overlap of colors. Every portion of the stamp receives its definitive color.
A bad engraving of the inking rolls will
cause an undesired overlap of colors; this is a frequent cause of varieties.
When the colors are released from the plastic inking roll to the metallic print cylinder, there is always an ink excess.
The fact is that the ink must remain confined exclusively into the print engravings, reason for which it is necessary a drying system; this is obtained through another plastic cylinder (drying cylinder), that work on the print cylinder surface with a going and return movement like a razor.
In this way, the ink remain alone into the engraving furrows.
The regulation of the drying cylinder it is very difficult: if the drying is excessive, it will remove too much ink from the engraving bottom and it will have a defective print, faded, said stripped.
On the contrary, if the drying cylinder is too loose, it will leave too much ink on the print cylinder surface and it will have a defective print for excess of ink, too grease.
Finally, if the drying cylinder for its
"going and return" movement, it spread the inks, we will have spotted prints
with stains and strips of colors.
The drying cylinder it is itself cleaned in permanent way by rotating brushes in tricoloroetilen. The print cylinder receives therefore its three colors, the drying cylinder removes the ink excess and the inking cylinder engravings released, under high pressure, their ink on the damp paper: the stamp is finally printed.
On the band of humidified paper, a band of transparent protective paper is overlayed; this paper, very thin, is said antispot, destined to protect the fresh print. Everything is subsequently indented and cut in sheets. The sheets, dried once, are separated one by one by the transparent protective paper.
It allows to print sheets from 10 to 100 stamps, carnets and roulettes.
It require two print groups each usying three colors; in the first group, a metallic cylinder receive three colors from three inking rolls each carrying one color.
But, important fact, the metallic cylinder doesn't print its colors on the paper, but on a plastic cylinder of even diameter; this cylinder is a intermediary that will bring again its three colors on the paper.
These three colors constituting the shade background and they are barely delimited among them and without reliefs.
This print by the plastic cylinder is said Amount
carried forward Recess Printing and it is very similar to the
A second group of three colors, identical to the T.D. 3 print, it is printed directly with a metallic cylinder on the paper that already includes the three background shades.
With this system we can obtain overlaps of colors and creation of numerous tones impossible to obtain with the normal T.D. 3 print.
This second group of three colors brought again directly on the paper by the metallic cylinder realizes the Directed Recess Printing; it is formed by slight relief clear lines touch perceptible. The Amount carried forward Recess Printing, realized by the plastic cylinder, is performed on dry paper that comes subsequently moistened for receiving the Directed Recess Printing. Once printed the six colors, the paper goes through a drying tunnel before being wound again. There is not need of antispot paper. The paper comes subsequently indented and cut in assembled sheets to the exit from the print machine.
This sophisticated technique is responsible of numerous varieties:
The first one (R.G.R. 1) it has been tested
in 1974 for the 0,50 Fr. "Marianne of Béquet" red n° 1666, but
the first issued stamp has been the 0,80 Fr. "Marianne of Béquet"
red n° 1811 in 1975.
This print machine, called also R.C.S. (Roto-Color Stampe), produces a T.D. 3 print (with 3 colors), on which can be added again a Photo-engraving print constituent or in Typography too.
It print 800 stamps for every cylinder revolution and it can print 20.000 sheets/hour.
The indentation is generated by a cylinder with 28.000 points, called urchin cylinder.
It has given rise to many ruling problems: some points are broken, creating spaces without holes of indentation.
Difficulty eliminating the corianders created by the indentation has also been the cause of many problems.
After 1985, a new Swedish machine eliminates the paper corianders gotten
by the perforation. A second type of High Efficiency
Rotary Recess Printing (R.G.R. 2) that
print with four colors engraving, it is entered in service in the January
1986 with the stamp type "Liberty" n° 2432.
It uses the same coinages of the R.G.R. 1.
In 1986 and 1987 it have been installed some new kind of prints: Rotary Recess Printing by Sheets. They associate Offset and Rotary Recess Printing.
On the sheets of Rotary Recess printed stamps one may find, depending on the period of printing and the type of press; six marks or numbers printed on the sheet margins:
The printing reference number has always existed since the beginning of the use of the rotary recess machines.
The printing date has also existed from the start, except that, after a time, it was not used for charity or commemorative issues.
The four other numbers or marks quoted above have undergone many variations over the years:
The first printing on rotary recess machines was made on 22.3.29, the stamp being the 10f La Rochelle (all stamps referred to are issues of France unless otherwise stated). The sheets only bore two identifying marks, the printing reference number and the printing date. All the stamps were printed on "three colour machines" (machines which are able to produce stamps with up to three different colours, by a process of depositing different coloured inks on different parts of the printing plate).
A new reference number was added to the sheet markings, taking the form of "I C 2"; the letter "I" was always used, possible standing for "indicatif"; "C" referred to the press operator, and "2" the number of" the press. This reference number was printed in large fat figures and the first sheets of stamps to bear it were those for Andorra printed on 29.4.33, and for France of 20.6.33 (2f Arc de Triomphe). The reference number is known to have been used until 8.1.64.
No additional sheet markings but omission of printing dates for charity and commemorative issues. Last known date 17.7.41 for the 1f plus 1f France d'Outremer. This system remains unchanged to date.
No changes except the appearance of additional distinguishing marks for each of the three sheets produced by one printing cylinder revolution ... 1, 2 or 3 dots ( ). The first sheets of stamps so marked were the 6f Andorre la Vieille of Andorra (19.7.45) and the 10f Marianne de Gandon of France (13.2.46). The system of dots continued in use until 1948.
The dot markings were replaced by a system of lines; 2 lines for sheet 1 ( || ), 1 line for sheet 2 ( | ), and no lines for sheet three ( ). This system was first seen on the 200f Airmail of France printed on 10.2.48, and continues to this day.
Markings unchanged but additional fancy "engine-turned pattern" printed on the previously blank stamp sized labels which appeared at the top and bottom, or sides, of the sheet according to the stamp format. This pattern was introduced to prevent stamps being forged on these blank, gummed, perforated stamp sized pieces of paper. The press number, and the operators identity reference is printed on top of one of these patterns, the sheet marking line(s) appearing alongside one of the patterns.
Markings unchanged. Introduction of new six colour machines; these presses bear reference numbers which follow on from the numbers of the three colour machines. From the time of their introduction an electronic mark was incorporated on one of each three sheets, and remains so today. The first stamps printed on these machines were the set of French bird stamps, without printing dates (coins-datés), of November 1960. The first dated stamp was the French "Marianne de Cocteau" (7.2.61).
Press number now in thin characters taking the form of "I D 4", "I" = indicatif: "D" = 4th letter of alphabet, therefore 4th press: and also "4" = 4th press. No longer any indication of operators identity. This new system started on 9.1.64 (1f Le Touquet) and only lasted until July 1964.
Press number now indicates type of press.
|e.g.||TD 3 4 =||Taille-Douce||3||colours||press||4|
|TD 6 2 =||"||6||"||"||2|
This system started on 1.7.64 for both types of machine, and continues today.
Appearance of new mark "RGR" - "Presse rotative à grand rendement" = High output rotary press. First seen on 25.7.75 for the 80c red Marianne de Bequet definitive issue of France. This system in current use.
As you will see the present position is that all sheets have the following marks:
or PHOTOGRAVURE): this proceeding has been
used later for the print; in the past, the Photo-Engraving
stamps have been commissioned to the private industry.
The oldest is the 1931 stamp for the Colonial Exposure n° 274, commissioned to the Typography Vaugirard.
Many post-cards have been printed with this method, also commissioned to the private industry.
The first stamp issued by the Government Printing House (Atelier) is the 0,20 Fr. n° 1503 (1966), although the first cylinders have been prepared for the private industry.
The stamp "Olympic Plays of Grenoble" n° 1520 it is the first one
in Photo-Engraving entirely conceived by the
Government Printing House in 1967.
The Photo-Engraving print start by a drawing without passing from a die (plate).
There is not an engraver artist for stamps printed with this method.
In the Photo-Engraving print, like in the Recess Printing, the furrows (hollows) prints and the reliefs gives the whites, but the color tonalities or the white ones are obtained beginning from very complicated photomechanical procedures and this multiply the error possibilities and therefore the probabilities to create varieties.
The Photo-Engraving print is easy to be
recognized with the magnifying glass; the lines are formed by a crowd of
minuscule united points but that, at a glance, gives the impression of
a uniform line (for juxtaposition).
The print is a rotary one, with metallic cylinders. Each color requires the manufacture of a metallic cylinder that will place this color entirely.
The sheets are from 25 to 100 stamps, but they can also be printed roulettes and carnets.
For technical reasons the Photo-Engraving
print requires white paper, bright, (plate paper), that allows to recognize
the stamps printed in Photo-Engraving print
with the simple look and the touch.
The print machine set to work in the Government Printing House in 1966 (Hél. 1) was conceived for printing in 5 colors; a sixth cylinder had been added in 1961.
A second 6 colors printing press (Hél.
has been put in operation in the December 1969.
A third press (Hél. 3) has started to print in 1984.