Seven good habits to improve CTP efficiency (below)

Fourth, quality management

Adopting the above workflow should also include minimizing the process of remastering, in one word: QC (Quality Management).

Tim Poole, chairman of Dome Printing Company, said: “We are always experiencing challenges in our daily business, so we do not know what kind of challenges we will face in using CTP.”

For example, the Sacramento printing house used film and proofs to check documents, and in the digital workflow, these two visual inspection steps were omitted. Instead, the plate is removed from the developer and printed directly on the machine.

The operator of the desktop production department checks the file on the computer and the next step is to print directly out of the printing plate. We must increase the number of testing steps to determine when it is officially printed on the machine. This is a big challenge, because we set up the detection point is not enough.

Bowne of Howston’s digital prepress manager also agreed with this view, saying: “Once a CTP workflow is selected, prepress testing becomes more important. It takes enough time to prepress prepress. It must be reviewed. Each component of the document ensures that the final image on the plate can be directly printed on the machine, at which point the plate becomes a metal proof."

The Bowne of Houston also performed a beta test on Topsetter, a Heidelberger platemaking machine. Topsetter is supported by multiple Macs, and two Heidelberg Signa Workstations output hard proofs. The printing company has web printing presses and sheetfed printing presses. The pre-press department had only 11 workers and implemented a three-shift system, but in 1999 the output value of the department reached 120 million US dollars.

Dome has established a multi-step quality management program. When a job first enters the company, it is first checked by a supervisor and then sent to the prepress staff for prepress quality testing. After the spelling is completed, the imposition staff is responsible for making proofs, and then making a printing plate, and is responsible for any modification of the proofs from the customer. Another imposition staff makes the final modification before the plate is printed on the machine.

Quantum's production process also includes the final inspection of the plate before imaging. The inspection method is to check the trapping and color of the file on the screen. The past quality control steps are performed on the film. Heinzmann half-jokingly said: "We used the $50 viewing platform for quality management, and now we use the $3,000 RIP to complete this step."

Once the plates have been prepared, the contents of the plates should be carefully examined. Quantum invested in an Acme plate reader to measure technical specifications such as tone reproduction density on plates.

Fifth, continue to learn

The experience of using workflows is important, but training is equally important. According to Fairley, at Johnsbyrne, training for employees began a year ago with the introduction of CTP equipment. The Perfection Press company provided imposition training for all staff. After the installation of the Presstek Pearlsetter CTP system, the operator received a two-hour training on Harlequin RIP operation.

Don't forget the customer when considering the trainee. Blooming Color and Johnsbyrne have trained customers through postal methods and used brochures to explain the differences in CTP workflows and film workflows. Johnsbyrne even held an information seminar.

Sixth, using dot proofing

Is it necessary to invest in a high quality digital halftone proofing system? This depends on the type of printing job shop and the needs of the customer.

Quantum Color's approximately 85%-90% of the same sheet is made by an Iris proofer. Alan Cudahy, president of Quantum, analyzed: “From the management point of view, digital proofing is the weakest link in the CTP process and remains to be improved in many aspects.”

Scoville Press has used digital proofing for more than three years. Since it is not a high-end color printer, it can be proofed with a single Iris proofer and printed on the same sheet with an Epson printer.

Cavanah of Perfection Press stated that when using the Pearlsetter CTP system, proofing is the biggest challenge. Perfection Press has 2 Heidelberg GTO presses, 1 Adast press, 1 Agfa ChromaPress, 1 Xerox DocuTech and 2 Diddle narrow web presses, as well as a variety of post-finishing equipment.

Cavanah explained: "We care about what kind of sample customers expect." The company conducted a test comparison of Epson 9000 digital proofs with printed proofs. Make customers aware of the proximity of Epson digital proofs to analog proofs, and highlight the cost advantages of Epson's digital proofs, which are much cheaper than those of Colorkey or Matchprint. Cavanah tends to do short-lived prints around 5000 prints, and such customers do not like to pay extra for Colorkey or Matchprint proofs.

The Blooming Color Company is targeting the point of purchase advertising market and has high requirements for details. As a result, the company used Coriotte Angel's Spectrum digital half-tone proofing system to output the same copy, and the proofs were produced on an HP large-format color inkjet printer.

Seven, color challenges

Tim Poole of Dome Printing believes that the biggest challenge facing CTP is color management. The traditional workflow provides a series of fixed color standards. Simulation proofs are made by outputting film made of traditional printing plates for simulation proofing and pre-set dot gain values. While CTP and digital proofing have no fixed standards, proofing and plate making become variable, so many other aspects are also variable. No one knows that the CTP definitely wins the color standard.

In order to solve this problem, Dome has been working out the best industry standards and has taken a test program to find out how it can be used as a benchmark for printing. The process control tool of the American Printing Technology Foundation (GATF) is also suitable for solving this problem. Dome's web presses perform color control via Bruner's control system and QTI's closed-loop color system. In addition, the operator can take printed sheets during printing and scan with Heidelberg gray balance spectrum control device. Sheet-fed offset press for color control.

Quantum Color is also committed to the development of color management workflows. They plan to track the press to find out the most suitable printing conditions, and then create a prepress workflow that can be replicated for high-quality printing effects.

Successfully implementing CTP applications is not an easy task. It requires a wealth of knowledge of the workflow and can plan ahead, even with a little bit of luck. Zarwan of state street consultants pointed out: "CTP involved so many parts of the replication process that it became the center of the hot topics of digital proofing, printing plate, digital workflow, and layout."

However, hard work always pays off.




Source: China Design Printing Network