Standards for better results
Quality: To ensure optimal end products, printing companies and advertising agencies should define a project using industry standards.
Quality To obtain optimum end products, print shops and advertising agencies should define a job using standards. "Quality is when the customer's requirements are met!" This definition assumes that the customer knows what he wants - and that the print shop also knows what the customer wants. But does this alignment always take place in a customer meeting? Experience shows that the majority of discussions during the job meeting are about prices and less about the customer's requirements. Both advertising agencies and print shops are "partly to blame" for this. Much could be done to improve understanding between the two parties during the discussion.Things to know about print quality Advertising agencies usually produce the print data themselves. However, the print shops cannot always accept and output them without problems. If the advertising agencies only hand over PDF/X-3 files to the print shops, then the data exchange works much better. PDF/X-3 data is easy to produce and also easy to control in the latest professional version of Adobe Acrobat 7. If necessary, help is available on the website of the PDFX-ready initiative (see box).
Of course, an agency can also transfer "open data" from QuarkXpress, InDesign or other programs to the print shop. However, they must be aware that such data is not always transferred correctly: For example, the print shop does not always have the appropriate fonts, elements are missing, or program extensions (plug-ins, XTensions) are installed that make the exchange impossible. This usually leads to additional costs.
Print shops or prepress companies also specialize in converting a layout sketch from the advertising agency into a professional layout file geared to print production. Even though this ensures that the data can be output, it does not mean that the advertising agency will see the correct colors during visual inspection or local printing or proofing. This has to do with the fact that the print shop works with a precisely defined color space. The agency must therefore use exactly the same color space. This color space is precisely described by ISO standard 12647-2 and the associated ISO profiles (for more information, visit the Ugra website: www.ugra.ch).
However, the correct creation of the data is only the first step. Furthermore, it should be noted that a proof is not just a nice, colored (control) printout, but that it simulates the color space of the print shop based on the conditions there. Therefore, the proof must be verifiable. With the Ugra/Fogra Media Wedge CMYK, the correspondence between the proof and the print result can be checked using measurement technology. This enables the advertising agency to perform an output check and the print shop to perform an input check on the proofs. In this way, the colorfulness of the printed matter is also under control.
Benefits for the advertising agencyProofs unfortunately reproduce colors incorrectly if they are not viewed in the right light. This effect is called metamerism. According to the ISO 3664 regulation, proofs must always be evaluated under a standard light with a color temperature of 5000 Kelvin. To control the light metrologically, devices costing more than 4000 Swiss francs are necessary. Since such devices exceed the budgets of advertising agencies and printers, Ugra has launched a color temperature indicator for easy control. The indicator is a small colored strip that is stuck to the edge of a proof. If all the printed patches show roughly the same color, the light is within tolerance - if they show different colors, the light does not meet the requirements.
What advantages accrue to an agency that takes all these points into account? On the one hand, the documents can be accepted by the print shop without any problems, and on the other hand, it can re-measure the proof and thus determine that the data can be reproduced or printed with color accuracy. But despite all these measures, individual colors in a subject can deviate greatly from the original. If, for example, the advertising agency has defined the background of an ad with a large salmon red color, this background color may be printed with too great a deviation. Such special requirements must be communicated to the print shop and checked on site so that they remain within an acceptable tolerance.
Higher demandsOffset printing is normally capable of printing midtones (50 percent area coverage) within a tolerance of +/- 4 percent. This is also defined in the ISO standard. Midtones, especially if they are gray or tertiary colored, show clearly visible color deviations at this tolerance. However, many print shops cannot print any better, so the advertising agency has to accept this color deviation.
However, for certain high standing printed matter, printing must be carried out with a tolerance of +/- 2 percent. Only specialized print shops can do this - because it requires a certain amount of effort, which results in higher costs and prices. The Color Balance Hexagon from System Brunner shows the color fluctuations to be expected in
a gray midtone at +/- 2, +/- 4 and at +/- 6 percent.
In order for the print shop to be able to check on the press whether the inking is uniform across the entire press width, it must print a control strip on the front edge of the sheet or in the middle of the sheet and uses a color measuring and control system integrated in the press to control the inking. We often hear from printers that they cannot afford the additional 1 centimeter or so of paper needed for the measuring strip. But thanks to the metrological procedure, a job can be set up in much less time. Therefore, much more money can be saved by printing control strips along with the order than with the supposed saving of paper by omitting this control means. Another objection is that the customer is not being sold control strips, but the job. For this reason, methods have been developed that take measurements in the printed image. However, these have not yet been successfully introduced in the printing industry.
The control strip is still a prerequisite if print production is to be measured and controlled. The measured and stored data can also be used for quality control. This makes it possible to find out where there is still potential for improvement. Without such data and evaluations, the companies are not in a position to continuously and specifically develop quality further.
How to recognize differences?The following list shows how to recognize an advanced print shop:
1. the printer wants to know the customer's requirements.
2. the printer knows what PDF/X-3 is, how to use it and/or is PDFX-ready certified.
3. the printer works according to a standard (ISO 12647-2, System Brunner Eurostandard, etc.).
4. the print shop requires proofs with a media wedge and also measures this. The print shop's proofs also contain the media wedge.
5. proofs are provided with a Ugra color temperature indicator, or the print shop at least knows under which light proofs are to be viewed - and also asks the advertising agency to adhere to this.
6. the printing house uses an integrated color control system on its printing press(es). Upon request, it can even show a quality report of the printed run.
PraxisDruckereien are reluctant to inform customers of errors in the planned job sequence. They would rather put up with extra work than point out to the customer that even small changes to the job sequence lead to better quality. Print shops fear that their comments will be perceived as a nuisance and that they will lose the job. This shows that there is something wrong on both the print shop and the customer side: The print shop is still the specialist for producing the print product - a customer should be happy if the specialist thinks along and makes suggestions. That's why an advertising agency should not just regard the print shop as the final authority on the path to the print product, but involve it in the definition of the job at a very early stage. This is the only way to achieve an optimum result for both sides.
Erwin Widmer is an engineer HTL and
Managing Director of Ugra.
PDFX-readyThis initiative allows data creators and data processors to become certified. The certified companies are listed on the website: www.pdfx-ready.ch. (ew)
StandardizationBy standardization, we actually mean nothing other than unambiguous communication, namely the consistent use of uniformly defined terms, units of measurement, interfaces, and data formats, as well as concretely specified dimensional figures including tolerances. Nevertheless, tolerances should always be explicitly discussed with customers and partners. On the other hand, tolerance specifications are not strict enough for some high-quality applications, for example in pharmaceutical packaging production; in these cases, some print shops produce according to self-imposed Good Manufacturing Practices or national Codes of Practices. (dk)
Quality toolsA test form is used to clarify a technical question. It is impossible to produce a test form that can satisfy all questions.
The Altona Test Suite is very well adapted to the conditions in the prepress stage. It consists of three test forms. The most important of these is the Visual test form. With this, a RIP belonging to a proofing device can be put through its paces. The total of three test forms can also be used to determine in a metrologically flawless manner whether a print shop can output PDF/X-3 data and print in accordance with ISO 12647-2.
System Brunner developed a test form for evaluating offset printing years ago. It is mainly based on the evaluation of three-color overprinting. (ew)
Color Balance Hexagon from System Brunner shows the color variations to be expected.
The Altona test form is primarily used to test raster image processors (RIP) that are part of proofing devices.
Light is close to 5000 K (top),Light deviates too much from 5000 K (bottom).
With the Ugra/Fogra control strip, parameters such as dot gain, trapping, gray balance, etc. can be checked.
Proofs are metrologically verifiable thanks to Ugra/Fogra media wedge.
GretagMacbeth's EyeOne Share software presents lighting parameters for profile creation for digicams.
System Brunner propagates the harmonization of the color and detail reproduction of all presses in a company to one standard.
Beginning of the Altona 29 characterization table, the data of which can be offset against ICC profiles calculated on the basis of the ECI-2002 chart.
GretagMacbeth's EyeOne Share software presents lighting parameters for profile creation for digicams.
With the PCM Online Tool, Medigraph offers a solution for standardizing the complete color reproduction and tonal value transfer chain.
Various measuring device and proofing technology manufacturers offer solutions for evaluating the media wedge.
The OptiCal software for the Pantone/ColorVision Spyder Pro monitor colorimeter complies with ICCv.41.
The most modern profiling test chart (ECI 2002) and the most important control means (media wedge, step wedges, solid bars) can be found in the PDF file Altona Measure from the Altona Test Suite.
Plate gauges are better than densitometers for plate measurement.
The Fogra CtP test form can be certified as a reference for linearizing imagesetters.
Erwin Widmer
Of course, an agency can also transfer "open data" from QuarkXpress, InDesign or other programs to the print shop. However, they must be aware that such data is not always transferred correctly: For example, the print shop does not always have the appropriate fonts, elements are missing, or program extensions (plug-ins, XTensions) are installed that make the exchange impossible. This usually leads to additional costs.
Print shops or prepress companies also specialize in converting a layout sketch from the advertising agency into a professional layout file geared to print production. Even though this ensures that the data can be output, it does not mean that the advertising agency will see the correct colors during visual inspection or local printing or proofing. This has to do with the fact that the print shop works with a precisely defined color space. The agency must therefore use exactly the same color space. This color space is precisely described by ISO standard 12647-2 and the associated ISO profiles (for more information, visit the Ugra website: www.ugra.ch).
However, the correct creation of the data is only the first step. Furthermore, it should be noted that a proof is not just a nice, colored (control) printout, but that it simulates the color space of the print shop based on the conditions there. Therefore, the proof must be verifiable. With the Ugra/Fogra Media Wedge CMYK, the correspondence between the proof and the print result can be checked using measurement technology. This enables the advertising agency to perform an output check and the print shop to perform an input check on the proofs. In this way, the colorfulness of the printed matter is also under control.
Benefits for the advertising agencyProofs unfortunately reproduce colors incorrectly if they are not viewed in the right light. This effect is called metamerism. According to the ISO 3664 regulation, proofs must always be evaluated under a standard light with a color temperature of 5000 Kelvin. To control the light metrologically, devices costing more than 4000 Swiss francs are necessary. Since such devices exceed the budgets of advertising agencies and printers, Ugra has launched a color temperature indicator for easy control. The indicator is a small colored strip that is stuck to the edge of a proof. If all the printed patches show roughly the same color, the light is within tolerance - if they show different colors, the light does not meet the requirements.
What advantages accrue to an agency that takes all these points into account? On the one hand, the documents can be accepted by the print shop without any problems, and on the other hand, it can re-measure the proof and thus determine that the data can be reproduced or printed with color accuracy. But despite all these measures, individual colors in a subject can deviate greatly from the original. If, for example, the advertising agency has defined the background of an ad with a large salmon red color, this background color may be printed with too great a deviation. Such special requirements must be communicated to the print shop and checked on site so that they remain within an acceptable tolerance.
Higher demandsOffset printing is normally capable of printing midtones (50 percent area coverage) within a tolerance of +/- 4 percent. This is also defined in the ISO standard. Midtones, especially if they are gray or tertiary colored, show clearly visible color deviations at this tolerance. However, many print shops cannot print any better, so the advertising agency has to accept this color deviation.
However, for certain high standing printed matter, printing must be carried out with a tolerance of +/- 2 percent. Only specialized print shops can do this - because it requires a certain amount of effort, which results in higher costs and prices. The Color Balance Hexagon from System Brunner shows the color fluctuations to be expected in
a gray midtone at +/- 2, +/- 4 and at +/- 6 percent.
In order for the print shop to be able to check on the press whether the inking is uniform across the entire press width, it must print a control strip on the front edge of the sheet or in the middle of the sheet and uses a color measuring and control system integrated in the press to control the inking. We often hear from printers that they cannot afford the additional 1 centimeter or so of paper needed for the measuring strip. But thanks to the metrological procedure, a job can be set up in much less time. Therefore, much more money can be saved by printing control strips along with the order than with the supposed saving of paper by omitting this control means. Another objection is that the customer is not being sold control strips, but the job. For this reason, methods have been developed that take measurements in the printed image. However, these have not yet been successfully introduced in the printing industry.
The control strip is still a prerequisite if print production is to be measured and controlled. The measured and stored data can also be used for quality control. This makes it possible to find out where there is still potential for improvement. Without such data and evaluations, the companies are not in a position to continuously and specifically develop quality further.
How to recognize differences?The following list shows how to recognize an advanced print shop:
1. the printer wants to know the customer's requirements.
2. the printer knows what PDF/X-3 is, how to use it and/or is PDFX-ready certified.
3. the printer works according to a standard (ISO 12647-2, System Brunner Eurostandard, etc.).
4. the print shop requires proofs with a media wedge and also measures this. The print shop's proofs also contain the media wedge.
5. proofs are provided with a Ugra color temperature indicator, or the print shop at least knows under which light proofs are to be viewed - and also asks the advertising agency to adhere to this.
6. the printing house uses an integrated color control system on its printing press(es). Upon request, it can even show a quality report of the printed run.
PraxisDruckereien are reluctant to inform customers of errors in the planned job sequence. They would rather put up with extra work than point out to the customer that even small changes to the job sequence lead to better quality. Print shops fear that their comments will be perceived as a nuisance and that they will lose the job. This shows that there is something wrong on both the print shop and the customer side: The print shop is still the specialist for producing the print product - a customer should be happy if the specialist thinks along and makes suggestions. That's why an advertising agency should not just regard the print shop as the final authority on the path to the print product, but involve it in the definition of the job at a very early stage. This is the only way to achieve an optimum result for both sides.
Erwin Widmer is an engineer HTL and
Managing Director of Ugra.
PDFX-readyThis initiative allows data creators and data processors to become certified. The certified companies are listed on the website: www.pdfx-ready.ch. (ew)
StandardizationBy standardization, we actually mean nothing other than unambiguous communication, namely the consistent use of uniformly defined terms, units of measurement, interfaces, and data formats, as well as concretely specified dimensional figures including tolerances. Nevertheless, tolerances should always be explicitly discussed with customers and partners. On the other hand, tolerance specifications are not strict enough for some high-quality applications, for example in pharmaceutical packaging production; in these cases, some print shops produce according to self-imposed Good Manufacturing Practices or national Codes of Practices. (dk)
Quality toolsA test form is used to clarify a technical question. It is impossible to produce a test form that can satisfy all questions.
The Altona Test Suite is very well adapted to the conditions in the prepress stage. It consists of three test forms. The most important of these is the Visual test form. With this, a RIP belonging to a proofing device can be put through its paces. The total of three test forms can also be used to determine in a metrologically flawless manner whether a print shop can output PDF/X-3 data and print in accordance with ISO 12647-2.
System Brunner developed a test form for evaluating offset printing years ago. It is mainly based on the evaluation of three-color overprinting. (ew)
Color Balance Hexagon from System Brunner shows the color variations to be expected.
The Altona test form is primarily used to test raster image processors (RIP) that are part of proofing devices.
Light is close to 5000 K (top),Light deviates too much from 5000 K (bottom).
With the Ugra/Fogra control strip, parameters such as dot gain, trapping, gray balance, etc. can be checked.
Proofs are metrologically verifiable thanks to Ugra/Fogra media wedge.
GretagMacbeth's EyeOne Share software presents lighting parameters for profile creation for digicams.
System Brunner propagates the harmonization of the color and detail reproduction of all presses in a company to one standard.
Beginning of the Altona 29 characterization table, the data of which can be offset against ICC profiles calculated on the basis of the ECI-2002 chart.
GretagMacbeth's EyeOne Share software presents lighting parameters for profile creation for digicams.
With the PCM Online Tool, Medigraph offers a solution for standardizing the complete color reproduction and tonal value transfer chain.
Various measuring device and proofing technology manufacturers offer solutions for evaluating the media wedge.
The OptiCal software for the Pantone/ColorVision Spyder Pro monitor colorimeter complies with ICCv.41.
The most modern profiling test chart (ECI 2002) and the most important control means (media wedge, step wedges, solid bars) can be found in the PDF file Altona Measure from the Altona Test Suite.
Plate gauges are better than densitometers for plate measurement.
The Fogra CtP test form can be certified as a reference for linearizing imagesetters.
Erwin Widmer
