In the world of printing, the 1980s was an era of transformation, when mechanics and manual labour began to give way to digital technology. One of the symbols of this revolution was the Heidelberg CPC (Central Printing Control) range of digital printing controls. These modules ushered in a new era of automation, offering solutions that radically simplified and accelerated the work of printers.
With the introduction of the first CPC models, the printing process became more predictable and controllable than ever before. The ability to set parameters for ink, moisturising and other critical processes via a digital interface has greatly improved consistency and print quality. But most importantly, these devices have become the bridge between man and machine, allowing prepress data to be integrated with actual print parameters for the first time.
This article will explain how CPC devices have evolved from version to version, what they have brought to the industry and how Heidelberg has moved closer to a fully automated print production with each step. Those rare photos that I managed to collect in advertising leaflets from forty years ago, let’s save them for history.
CPTronic
First of all, the CPTronic machine control system should be mentioned. For the first time in the world, an attempt was made to introduce smart algorithms for controlling the supply of dampening solution, ink and air into printing machines by means of characteristic curves depending on the printing speed. Many people confuse CPTronic with the CPC control panel. But they are completely different devices.
The CPTronic was used to set the printing plate and adjust the ink register. In short, the CPTronic is the brain and nervous system of the machine, connected to its various components by wires. In this way, the printing process became much more predictable. The machine operator was now able to adjust and correct basic parameters without leaving his desk.
As the CPTronic improved, more and more sensors were added to the machine to tell the system the status of a particular parameter. It was there that the characteristic curves of speed-dependent control of print parameters were recorded.
CPC 1
The CPTronic control panel was a freestanding console located to the right of the CPC control panel, which is why many people think of them as a single unit. But that’s a bit of a misnomer.
The CPC was a convenient console for controlling the printing machine – colour zones, plate drive – while the CPTronic was responsible for interfacing operator commands to the machine.
Depending on the configuration of the printing machine, there were many versions of the control panel.
With each new version, the CPCs became increasingly intelligent and integrated, gradually transforming Heidelberg printing machines from fully mechanical to high-tech systems with automation and minimal human intervention.
CPC 1-01
Year of introduction: 1980
The first digital control system for sheetfed printing machines. Main purpose was manual adjustment of colour zones using a simple digital interface. Did not involve integration with other processes.
CPC 1-02
Year of introduction: 1982
Introduction of characteristic curves dependent on printing speed. This improved the accuracy of ink and dampening control. The system remained localised, with no link to prepress processes.
CPC 1-03
Year of introduction: 1984
Added the ability to memorise settings for repeat jobs, which simplified debugging. Introduced the basic concept of data transfer via special cards that were used to set up colour zones, but this was a local system not linked to external standards.
CPC 1-04
Year of introduction: 1986
Introduced at Drupa 1986. This version introduced the ability to work with digital cards containing colour zone data that could be transferred from a prepress plate scanner (built into the CPC 3). This technology predated the CIP3 standards, but was a closed Heidelberg system.
The CIP3 (International Cooperation for Integration of Prepress, Press and Postpress) standard was created in 1995-1996. These clarifications show that the Heidelberg CPC 1-04 technologies were the prototype of today’s integrated systems, but without the standardisation that came later.
CPC 2
The main parameters of the printing process were assigned corresponding numbers. For example, CPC 2-C was responsible for the spectrophotometric control of the printing process. Heidelberg deliberately took a more complicated route, deciding to base the measurement not on the optical density of the ink, but by determining colour coordinates in the CIE Lab system, which are then converted into the adjustment parameters of the ink unit gates on all (!) ink units. Can you imagine?
Of course, the company has also thought about the fact that the colour ductor will eventually wear out on the colour knife. If you’ve ever walked up to an old printing machine, you’ve probably seen a scratched ductor cylinder. But not on Heidelberg machines.
The CPC colour box has been designed in such a way that neither the ductor nor the knife have direct contact. That is, there is nothing to wear out in this pair. For wear and tear, a replaceable white polyester film was designed to be changed along with the cleaning of the paint box. The design was so successful that it is still in use today without much change.
CPC 3
This part was responsible for transferring data from the prepress process to the machine in order to reduce set-up time. In 1986, there was no CIP3 standard yet, or even a link to the plate process. Let me remind you that the plates were made from photographic films in a copy frame, and it was all done manually. It was worth changing the film developing temperature slightly, as the raster dot would increase. There was a concept of ‘veil area’ for photographic materials that changed with changes in developer temperature, exposure time, and development time.
Those who caught on to analogue photography can still remember how difficult it was to get the gradient right. When making a plate, the same factors occurred. You can imagine how much the printing process in those years depended on the skills of people in different professions. It was logical to set up the printing process not by the photographic film, but by the end result of the printing plate making process – after developing and processing.
This is what the very first system of scanning printing plates looked like.
In the second half of the 90s, the device changed its appearance and became vertical. The data was recorded on a special magnetic card that could contain setup data for up to 50 orders. The latest versions – CPC 31 even had the option of attaching the CPC 32 online to a printing machine for direct transfer of scanned data to the machine.
CPC 32 – Prepress Interface
So the CPC 31 was a plate scanner. Before printing, the operator scanned each plate, recorded its data on a special CPC card, and then inserted it into the machine’s control panel. The press automatically adjusted the colour zones. This process was calibratable and reduced machine set-up time.
Later, in 1990 with the development of computers and photo typesetters came the CPC 32, Prepress Interface. It was created for the first digital printing machine, the GTO 52-4 DI, where plate making took place inside the machine. The plate scanner was produced for a while, and to avoid confusion with the electronic device, it was renamed CPC 31.
The first compatible Heidelberg system appeared with the CPC 32, which was integrated with the prepress process via the Prepress Interface (PPI). It was a PC-based computer workstation with a special interface for connecting a printing machine. Therefore, unfortunately, we do not have a photograph of this device.
CPC 4
Finally, the CPC 4 was designed for quick register setting. The first version looked like a small sized box that looked like a densitometer. It was located on the control panel of CPC 1 table. When the printer set the plates and made a proof, he would scan the side crosses with this device. Even the printing machine automatically did the colour matching within ten seconds. This was also a small revolution, because a printer with experience, doing the colour matching manually, could do it in about five minutes.
In 1995, an even more modern version of the CPC 42, the Heidelberg Autoregister, was introduced. After the last print unit, a scanning ruler was installed, which checked the register during printing. What was the most importantly, it controlled the registration throughout the printing process!
The scale replaced the usual crosses for checking alignment, and took up only 5 mm on each side of the printed sheet.
CPC 5
In the second half of the 90s, CPC 5 was also presented, which referred to the production management system. The company’s management could control the machine load, determine the economic parameters of the output. But this system in those years was not yet so developed, so we will just mention it here. Complete solutions, which started from prepress processes and ended with postpress processes, began to appear a decade later, based on the JDF format.
The next phase of the CPC system upgrade came in 1996, a year after DRUPA.
Managing Director Hartmut Mehdorn acquired the Stahl-Brehmer plant in Leipzig, the Linotype-Hell plant in Kiel. At the same time, the Sheridan plant in the USA and even Harris, which produced rotary printing machines, became part of the Heidelberg Group. It became clear that the new system had to integrate all processes into one production management system. The old system could not cope with the new requirements and needed a major upgrade.
A couple of years later, Heidelberg became one of the founding members of the CIP3 data transfer format. As a result, all equipment will be able to ‘understand’ each other. Only then is it possible to integrate the entire printing process into a single production management system.
New generation
And in 1999, Heidelberg introduced its famous CP2000 touchscreen control panel to the market. This was not just a machine control device. It was a full-fledged computer with a spare parts catalogue, operating instructions and, most importantly, a user-friendly interface. Something similar in terms of functionality had only begun to appear in the competitors by 2006.
In 2000 the era of CPC components was left behind. All elements of the system received a new name – Prinect. Heidelberg has thus gone even further in terms of print automation and has once again left all competitors behind.
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