Production of a stamp at Postado

at the example of the new stamps for the anniversary of the Augsburg Zoo by LMF Postal Services.
The graphics department of Augsburg Zoo has, after consultation with the prepress experts at Postado, produced a PDF with the correct technical basis and sent this to Postado. For details on the data sheets in the production catalog on pages 50-53, or here.

A version of this description for children and adolescents from 10 years can be found here.

Layouting stamp sheets

LMF stamp sheet "75 years Augsburg Zoo"
LMF Briefmarken

Postado recommends to create a stamp sheet with the format of 20 x 12cm, since this format can be sent well in a DIN-long envelope even in thicker stacks. To use a standard cutting die, it is necessary to place marks with a 5 mm distance to one another. As stamp format LMF Postal Service chose 40.8 x 30.8 mm. LMF Postal Service has decided to perforate the sheets to separate single stamps easily. In the same way, the sheets are created for 5 different value levels. These were produced with self-adhesive material.

Prepress

Proof with imprints
LMF Proof
Mr. Guntermann at the prepress department
Prepress worker
Test print
Plot

The prepress department and a high-end RIP check if everything in the PDF files is correct for printing on standard offset. All dimensions have to be 100% accurate to fit the cutting die exactly. Colors are checked, the resolution and quality of images, the integration of the fonts, the correct house colors of LMF, the positioning of the stamps and even more is examined. After the test and the RIP-procedure, where a flat 1bit TIFF file is generated, which was made by mail, also a contract proof was produced, which depicts the color impression from offset almost exactly, and thus provides a good opportunity to give a first impression of what is later printed.
While the paper proof is on its way to LMF via post, the prepress deparment already starts to set up everything for production. Thereby the small stamp sheets are arranged on a large sheet, so that several stamps can be printed together. Attention is paid precisely to the distances of the individual mark sheets. A spread is about 50 x 70 cm, the layout is optimized and packed up to the last inch. In the next step a test print is produced, on which all distances and dimensions are checked again. This print now includes all important imprints for offset printing. In the meantime, the approval of the contract proof and the ripped PDF file have been done by LMF.

Printing plate

Files are OK, LMF has approved the data and the print data is all prepared. Now the four printing plates for cyan, magenta, yellow and black are produced. The platesetter is an environmentally friendly thermal imager for direct exposure, this saves a lot of energy, water and chemicals. Inside the platesetter there is a strong laser that exposes the image on the plate that should be printed. The plates are washed out in the press. The image-parts are hardened and fat-friendly. There thus is liable to "greasy" ink, the rest of the plate is bare aluminum and thus water-friendly. On that oil and water based offset printing (for details in offset printing technology see e.g. de.wikipedia.org/wiki/Offsetdruck). With the 3 primary colors and their mixtures can be created about 1.3 million colors, black is for the contrast, and does not apply to us as a color. If you look at a printed image with a magnifying glass you can see a lot of small dots, they only consist of cyan, magenta and yellow points, which create an optical illusion.

production of printing plates
production of printing plates
color separation
color separation

Printing

The plates are clamped into the machine. The color is then passed on to a rubber blanket, and this prints on the paper. Paper is a very hard and rough material (in a microscopic point of view), so we need a "soft" blanket as transmitters. At the control panel the fitting of the individual colors to each other and the amount of color is set. Therefore sheets must be controlled again and again to check. This check happens at the beginning visually under standard light. The printed sheet is compared with the contract proof, if that is satisfactory, a densitometer is used to measure the strict compliance with the standard values. These values are important for a later reproduction, so that the color will be almost identical.

Paper at infeed
paper
white paper running into machine
infeed
plate and ribbon blanket
cylinder
control panel and measurement device
panel
four color printing machine
PM74
stack with printed stamps
print run

Numbering

After the signatures were drying at least 24 hours, they will be halved for the next machine. Because the cut is done at very high pressure, the sheet must be completely dry, otherwise smeared print or a ghost image could be seen on the back of the sheet. For safety and ease of counting the sheets of stamps are now numbered. This is done with numbering tools (instead of a pressure plate), which increases the numbers after each print. In this machine four stamp-sheets are worked on simultaneously. This happens with the regular edition, that is the amount ordered by LMF. Then again there has to be a drying process and the four sheets are divided again, this time resulting in single sheets.

stamps in cutter
cutter
halfed sheets in machine
Gto46
numbering tool
numbering
 

Diecutting

Heidelberger Tiegel diecutting
Tiegel
die cutter
metal plate

For the diecutting process a "Heidelberger Tiegel" is used, which is an old letterpress machine. A gripper picks each individual sheet and places it on a hard steel mold, then a heavy steel head pushes the blade with several tons of pressure against the die. The whole thing is set so that the stamps are punched and can be easily peeled off the carrier foil. In the middle of two stamps the sheets are perforated at the same time, so that you can easily separate the individual stamps.

Finishing

After punching the sheets are trimmed to their exact dimensions. Thereafter, the paper is placed in stacks into a glue station and pressed firmly. At the head of the sheets glue is applied and then dried. After drying the paper stack is divided into individual blocks of 50 sheets and is provided with a start and end sheet.

glue station
glue
bundling
bundle
finished blocks
blocks
letters ready for mailing
letters with stamps

Stamp perforating

LMF Postal Service has ordered a second version of the stamps: wet-adhesive decoration sheets. When producing everything works similar to the self-adhesive stamps: checking printing data, creating proof-prints, obtaining approval, plotting, producing printing plates and printing.
Then a new machine is used: the stamp-perforation-machine punches holes into the paper. This machine uses rigid combs with steel needles. After the perforation the sheet is divided and numbered, then trimming takes place.

Stamp-perforation-machine
stamp perforation
Left: holes at the edges of the stamps aren´t correct Right: correct perforation, at the edges is excatly one hole
Scheme right and wrong
Schematic view of the perforation
Scheme
Finished decoration-sheet "Augsburger Zoo"
decoration sheet

First-day-card

Production is again similar to the self-adhesive stamps: checking printing data, creating proof-prints, obtaining approval, plotting, producing printing plates and printing. Numbering is provided here too. After that the cards are grooved, so you can fold the first-day-cards as easy as possible. To a part of the first-day-cards the new stamps are glued by hand and stamped carefully.

first-day-card No. 267
267
numbering tool
numbering tool

Information

This description shows one of the possible ways of production through our print shop, they are dependent on print runs, design and format. We didn´t describe, for obvious reasons, not to all controls and for the benefit of security we did not show all the safety features of the stamps.

Illegal copies of the text, the images or extracts thereof is prohibited. It is allowed to make a link to Postado or LMF-mail service.
© POSTADO © LMF Postal Service


A postage stamp, male, was elated
With joy, before he was dated.
A princess licked him, by Jove!
Which did awaken his love.
He wanted to kiss her back
But had to go on a trek.
His love was thus unavailing
So sad is often life's failing.

(translated of Joachim Ringelnatz´s poem "Ein männlicher Briefmark")