40401: My printer needs "colour-binding" output or a PDF / X-3 file.

Unfortunately, this topic is somewhat complicated, so here are a few remarks on the background:

Starting point are as often in life two parallel worlds, here they are the print technology and the computer technology. In computer technology, colours are encoded according to the RGB colour model (RGB = red, green, blue). The basic colour of each computer screen is black; the "more" you "use" of each colour, the brighter it becomes, and all three colours at maximum yield white. With the colour model, several million colours can be encoded, and according to the computer technicians, this is completely sufficient and more than enough, as that are more than the human eye can distinguish anyway.

On the other hand, there are the printing technicians, who naturally do not print on paper with a basic colour of black, and where the paper is not getting brighter / whiter when more colour is applied but darker. Also, the simple "reversal" of one colour model into the other is not a solution, since one would not seriously print larger entities of black by "superimposing" all other colours. (Imagine suggesting a painter, often referred to as an artist, to use all the other colours of his palette when he or she runs out of black.) Thus, it is inevitable in the printing industry to encode colours according to a colour model, which corresponds rather to the process sequence of printing. The CMYK colour model (CMYK = cyan, magenta, yellow and key for a black fraction) is customary for modern offset printing. In addition, colour profiles are required for the precise, device-independent definition of the colours expected by the printer.

The real problem is that the two-colour models are not directly "translatable" into one another, meaning, that there is no general "formula" on how to get from RGB to CMYK and colour profiles. Someone has to make one, more or less arbitrary, depending on the application-dependent translation of the colours. If your printing company tells you that they need a file with "colour-binding" information, this means that they cannot or do not want to assign the computer colours to the printing inks themselves. However, your computer hardware manufacturer will not contribute it either ...

Now you as an FBS user as well as us as iRFP, we stand between the seemingly hardened fronts of both worlds and now technical terms like "colour management", "colourfast", "ICC profile" or "softproof" are thrown at us - without us even knowing what we have actually done wrong.

What possibilities do you have in practice to deal with the problem? First of all, it is certainly important to know that no "1: 1 conversion" is possible. The RGB colour model can code more colours than there can be printed with CMYK + colour profiles in practise. Therefore, a loss of colour information when translating RGB to CMYK + colour profile is always possible and can never be excluded. A decision and, if necessary, responsibility must be taken over by someone.

Yet, in our opinion, in practice the problem is not as dramatic as it may seem from these theoretical explanations: one should ask the question of the importance of the exact colour information in the timetable documents, while remaining reasonable. In the context of timetables, the issue is more or less a matter of drawing lines and tables, and practically never about pictures in the sense of photos or even paintings. Thus, table and arrival and departure posters were traditionally printed in black-and-white or black-and-yellow (so shown in two colours), without any information in the colour itself. Therefore, there are no colour specifications (in the sense of CMYK + colour profile), which could be consulted for the actual timetable. Rather, it is assumed that it does not matter which colour a traveller sees exactly – he or she should always understand the contents of the route independently from that.


When the problem presents itself to you as an FBS user for the first time, we recommend the following considerations:

  • Check if the exact colour reproduction is important for your timetables. If you share the attitude that it is not, authorize or instruct the printing institution to make an analogous assumption for the colour translation – which definitely does not mean to print all the other colours on top of each other in order to have black.
  • If your FBS timetable documents contain, for example, company logos whose exact colour rendering is important, do not include these logos directly in the FBS documents. In this case, you must have a template of the logo that contains CMYK + colour profile information. (It is to be assumed that this information has been transmitted by the person or service that designed the logo together with the logo itself.) FBS can only process RGB-based formats because it must first display the logos on the monitor and so the CMYK + colour profile information would be lost. Instead, transfer the original logo separately to the printing institution.
  • If other requirements apply to the colour reproduction, then these are usually not in the actual timetable documents, but, e.g. from advertising, which is to be printed together with the timetable documents. As a timetable technician, you may have to (if necessary) pass the decision on the exact colour reproduction to the places which issued the corresponding elements.
  • You maybe cannot expect a "print shop" or a "copy shop" to perform a "true" colour translation or one “corresponding to the corporate philosophy". It is possible to expect this from a special company specializing in presentation, graphics and design. To this extent, it may be necessary to include such a company with the processing of the documents to be published, provided that your company attaches great importance to accurate colour reproduction.

We as iRFP assume that the FBS tables will be included in a layout / set programme, as a result of the frequently diverse non-railway operating information desired on the timetable pages to be published (e.g. advertising). FBS is not a layout programme in the sense of printing technology but in a timetable construction system.

Last update on 20.03.2020 by iRFP Support.

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