Technology has touched practically all aspects of our lives. But not all advancements have been accepted with open arms; history has shown man to avoid "new technologies" that were either too radical or unfamiliar. Direct-to-plate printing technology appears to fit into this category. However, the benefits of direct-to-plate (DTP)-enhanced quality, environmental friendliness, higher productivity through electronic imposition, and lower production costs-are valuable enough to convert any skeptical printer.
Dr. Jerry Waite, of the University of Houston, once said, "Quality is in the eyes of the beholder...in other words, the customer decides what is a quality job." To produce a high quality product, printers must attempt to duplicate the order as close as possible to what the client has in mind. Printers, however, encounter dot gain, a characteristic inherent in all major printing processes. The use of film during platemaking and the actual pressrun both tend to increase the size of halftone dots (Adams, Faux & Rieber, 1996). Although compensations can be taken into account using profiles and fingerprinting, the removal of these steps would certainly prove time- and cost-efficient.
Using film to burn plates is still preferred throughout the printing industry. However, the potential problems affiliated with this process are numerous. Film with insufficient density can cause dot gain, dark highlight areas, and plugged-up shadow areas. On the other hand, film that is too dense can result in washed out images (Blatner & Roth, 1993). Other potential problems related to film include scratches, dimensional instability, drift factors during plate exposure, and variations caused by alignment and stripping by hand (Maas, 1995). Direct-to-plate technology tackles these obstacles by "eliminating film, such as color separations, duplicate film and final film" to enhance image quality (Fenton, 1998). With film gone, however, the role of the printing plate becomes very important.
Without the use of film to transfer images onto plates, platemaking technology has had to evolve to fit into the direct-to-plate process. For example, Kodak developed the Direct Thermal Printing Plate. While many plate suppliers use silver halide or photopolymer technologies to address the demands of direct-to-plate, the Direct Thermal Printing Plate uses thermal imaging techniques, an approach endorsed by the Graphics Arts Technical Foundation. This plate "is based on applying focused heat from a laser diode to the surface coating on the plate until a threshold temperature is reached. At this point an image is formed precisely as written by the platesetter. If more heat is added above the threshold nothing happens. The image does not change. The image is exactly as from the prepress system with no dot gain" (Kodak Limited, 1996). Kodak claims that its plate can hold image detail and resolution of 4.8 microns, equivalent to a one percent dot at 600 lpi. But perhaps the greatest advantage deals with the Direct Thermal Printing Plate's flexibility-it can be imaged both optically and digitally. In addition, its sensitivity to only heat and ultraviolet light allows the printer to handle the plate in common plateroom safelight conditions (Kodak, 1995). If left unchecked, dot gain can create enormous problems for the printer. Direct-to-plate alleviates this problem by eliminating the film, thus improving the quality.
Direct-to-plate printing technology is more environmentally safe than conventional platemaking technology. Both traditional film processing and plate processing involve hazardous substances. Although the latter cannot be removed from the entire printing process, platemaking produces fewer toxic substances than film processing. So the exclusion of film reduces a greater portion of the dangerous materials (Fenton, 1998).
Direct-to-plate can also result in higher imposition productivity, the process of arranging pages in the appropriate order for printing. With manual imposition, only single pages can be created and stripped together-it is quite labor intensive. On the other hand, direct-to-plate requires signatures to be imposed electronically. The result is increased productivity (Fenton, 1998).
Finally, there is the benefit of lower production costs. According to Fenton (1998), "the savings can result from imposition software, decreased stripping, decreased film, decreased processing and less work in the stripping, proofing and platemaking departments."
In the same way that all technologies have problems, direct-to-plate runs into some snags. The first involves proofing. Proofing at various stages of the printing process is not only vital, but is usually required by the customer. When using film, errors can be detected and corrected in any of the many steps prior to actually burning the plates. With direct-to-plate, however, there is no way to accurately judge the image being exposed onto the plate. There is no chance to strip-in corrections or to execute other remedies. Another problem with direct-to-plate deals with multiple press lines. Maas (1995) states printers "that rely on multiple press lines will no longer be able to burn a negative over again for duplicate pages on other press lines. Separate plates...will be required for each press line." The last pitfall with direct-to-plate technology is inconsistencies in plate manufacturing. "Direct-to-plate devices have to verify and correct plate-position misalignments.... Also, the number of impressions (plates) will run on the press has not yet been determined. Finally, production workers...will have to be trained to make pages on the computer in case a plate is destroyed near the end of the cycle" (Maas, 1995).
It is understandable to fear the unknown. Technological advancements throughout history have had proponents as well as opponents. But many new technologies have proven their worth in time. Direct-to-plate printing technology is another such advancement. Those who have already implemented the system have proved its benefits. Higher quality, ecological awareness, higher productivity, and lower production costs-these advantages can only be reaped by those printers who choose to adopt DTP technology.
Adams, J. Michael, Faux, David D., and Rieber, Lloyd J. (1996) Printing Technology.
Blatner, David, and Roth, Steve. (1993) Real World Scanning and Halftones.
Fenton, Howie. (1998) The Cold, Hard Truth About Computer To Plate [WWW document]. URL http://www.electric-pages.com/fenton/dir2plte.htm
Kodak Limited. (1996) Kodak and thermally imaged plate technology. [WWW document]. URL http://www.kodak.com/UK/en/whatsNewLimited/pressReleases/archive/kworgart.shtml
Kodak. (1995) Kodak Direct Image Thermal Printing Plate [WWW document]. URL http://www.kodak.co.uk/global/en/professional/ ppiCTP.shtml
Maas, Larry. (1995) Why We're Going Direct To Plate [WWW document].URL http:// www.naa.org/Technews/tn950304/p12why.html