Hong Kong Selects Digital Proofer Suppliers

With the popularity of digital printing, CTP systems and digital direct printing systems in recent years, color management (CMS) has become an important topic in the industry.

Among them, Digital Proofer has become an important part of the investment of various users because the traditional scripting system will certainly be replaced by Digital Proofing.

At present, many vendors offer a wide range of Digital Proofer systems, from large companies with the Digital Proofing System for the entire CTP process, to systems provided by some CMS system suppliers, and even some only inkjet printer agents. Thought that adding a software RIP that supports ICC Profile is equal to Digital Proofer and it is strongly promoted. For a time when the market is in full bloom, buyers may feel more confused and do not know how to choose a suitable system.

Most users will pay attention to the price of the system, the cost of consumables, and the speed of printing when purchasing Digital Proofer systems. Of course, we will also look at one or two demonstration samples. The above points are indeed important considerations for investing in a system, but many users are more ignorant of the supplier's own technical level and the correct steps for installing Digital Proofer.

In the years of CMS consultant work experience, the author found that the Digital Proofer problem encountered by users, in fact, has nothing to do with the technology of CMS and digital proofing; but the system supplier ignored many important steps in the installation of Digital Proofer, Make its Digital Proofer printing effect greatly reduced.

Any well-served CMS and Digital Proofer supplier must invest in high-quality hardware and software to produce ICC profiles, densitometers for linearization, and even their technicians' CMS expertise. Only in this way can we provide professional services and installation settings to an accurate digital Proofer.

Unfortunately, the author sees that many suppliers on the market currently try to cut corners when installing services. For example, only basic color settings are made. In the absence of ICC profiles, manual adjustments are made to the "canned" profiles of some manufacturers and RIPs. Two or three drafts will be completed, as long as the customer does not find the problem in real time, they can "bone." For example, the author finds that many Digital Proofers on the market do not do linear calibration at all. This is because the supplier does not have a density meter (or does not even know to do this step), plus the process is time-consuming, so many times when the customer does not make a request At that time, this process was saved.

The purpose of this article is to introduce the steps that must be taken when installing DigitalProofer. We hope that users who have purchased Digital Proofer will be able to understand the main points of the inspection system installation. Other users will also know how to choose a good Digital Proofer supplier.

(a) Print Head Alignment
Most Digital Proofers are now different size Inkjet printers. When the Inkjet printer's ink head is blocked or aligned, the printed manuscript will have a trace or a Bending condition. Use the additional tools in the printer driver to check if the ink heads are blocked, need to be cleaned, and align the ink heads. This is the basic and necessary job when installing Digital Proofer.

(B) Ink Limit and Linearization

To know that most of Digital Proofer's RIP is based on ICC Matching to simulate colors. The ICC Profile itself is not used for calibration. It simply records the color characteristics of the printing process or the printer or display so that the entire color flow can be communicated. Before doing the ICC Profile process (collectively referred to as profiling), you should do calibration—most of the quality Digital Proofer RIPs have Ink limit and Linearization settings.

Ink limit controls the amount of printer ink, too much may make the printer sample too much ink and long-lasting cracking, too little to make the printer can print out the reduced color gamut, thus affecting the effect of color simulation, so the amount of ink control must pay attention , And a variety of paper materials can withstand the different amount of ink, such as glossy Ink limit can be higher, matte paper Ink limit lower, so Ink limit must be done individually. However, in order to save time, many suppliers usually only set an Ink limit, even worse, they use the Default setting.

Linearization can improve the printer's linearity. Just as Image setter turns on every day, it also needs to check the film density to adjust the laser's energy and make the gray scale as linear as possible. If the Linearization process is erroneous, the most obvious is that some gradients will print. One thing to watch out for is to adjust Linearization in Digital Proofer's RIP. We use a density meter to enter the printer's data into the RIP. Also enter the standard data for the press (or drafting). Therefore, the density meter we use to measure the printer must be the same brand as the densitometer used by the printer or the drafting company to make the QC, so as to avoid data bias of different brand products.

The author once had the following experience in a large-scale printing factory: The manufacturer purchased a CTP and Digital Proofer from an internationally renowned manufacturer. After installation, his production manager complained to me that his Digital Proofer did not have a major problem with the basic hue, but when he printed some gradients, there was a serious situation that prevented the customer from accepting the Digital Proofer at all. At first he had been skeptical of Digital Proofer's technical problem because his supplier had already produced two appropriate ICC Profiles for him, and had checked and adjusted the printer for several months. However, when I checked his Software RIP settings, I found that the installation did not do Linearization at all, so there was a problem with the print gradient. After re-doing Linearization and updating the ICC Profile, the problem was solved. It can be seen that even if the services of large manufacturers are not so, users choose suppliers to be careful!

(III) Quality of ICC Profile Production

When making the ICC Profile, the software and hardware quality selected by the supplier is very important. There are many different brands of ICCProfiling software on the market, both large and small brands. However, there are generally not more well-known color Blind Color Blind Professional, Gretag Macbeth Profile Maker Professional, Colorl Heidelberg and Creo Scitex Profile Wizard and so on. A number of popular Software RIPs are also color-converted by Heidelberg, Color Blind, or Gretag Macbeth's CMMs - showing that their quality is particularly good and the accuracy is high.

It is also important that the spectrophotometer that reads the data be measured manually or automatically. The manual measurement will have the opportunity to make mistakes, and the automatically measured spectrophotometer will recalibrate the white level after measuring a certain number of cells, making the measurement data more reliable.

In order to save time, some vendors only print/print the ICC profile for the customer, and the printer itself only uses some "canned" profiles sent by Software RIP. Imagine these "canned" profiles and the actual use of paper and ink must have many deviations, so how can you do a quality digital copy? Last but not least, the ICC Profile also has 8-bit and 16-bit Profile points, while the latter will have more conversion table control points, and the overall conversion effect will be smoother and better. So pay attention to whether the CMS service provider uses 16-bit to calculate the ICC Profile.

With regard to the above points, after purchasing the Digital Proofer, the user must pay attention when installing the Digital Proofer, and do not receive the goods easily before completing all the steps.

Here are some small test checks, you can know if you have been "stupid" by the supplier, did not install Digital Proofer:

(1) Check if some “canned” ICC profiles are being used within the RIP. For example, these names are the ICC profiles provided by the factory.

E5000_ EPS6150_ CMYKcm_ DYE_ T20HQ_ D2_ 300999.icc

E9000_ BPSM6150_ CMYKcm_ DYE_ 720_ D2_ 300999.icc

E5000_ BPSM6150_ CMYKcm_ DYE_ 720_ D3_ 070200.icc

(2) Check if the linearization in the RIP is also some "canned" Linearization curve, as shown below:

(3) Try to make a 4-color gradient black rectangle from 0-100 in Quark, Freehand, or Illustrator, as shown in the following figure (3):

Then in the Court Under the Digital Proofer print, check whether the starting situation of this sample is very serious, and whether the gray tone will be red for a moment. If this is the case, it is likely that the supplier has not done a good job of doing Linearization or Linearization.

Finally, in order to achieve good CMS performance, or to get a good Digital Proofer, the user needs to clearly know every product he uses, and the supplier should also provide detailed data and training, so that the user can understand the In principle, it can fully play its due function.