Living Digitally in a Four-Color World
Proofing four-color jobs is more challenging than proofing one-color simply because four-color jobs are almost always more graphics-intensive, says Calvano. "We live in a visual world, so expect larger file sizes," agrees Andersen.
Just how much larger? "To give you an idea," says Bauer, "a black-and-white book typically is about 100 MB. A four-color book of the same page size is typically about 4 GB." Which is not to say that large, complex one-color files do not exist, Charlton says.
"In our shops," he says, "we use ... different methods for proofing one-color and four-color projects. The one-color method is simpler and faster."
However, he adds: "As far as proofing one-color for quality, we have not yet found a digital one-color proof that will satisfy our customers. The four-color digital proofs used for press checks though are very good."
More color, more savings
Savings in a four-color workflow are much better than with one-color, Charlton continues. In fact, the cost of one-color reprints is higher when done CTP than when done conventionally, he says. Black-and-white CTP savings due to workflow reduction are more dramatic up to the point when a file arrives to the printer's prepress division, Calvano says. "Once there, however, the printer's fixed costs of equipment investment, labor, plates, etc., are not really driven down substantially by having received only one-color files."
Workflow reduction is definitely more evident in the graphic-intensive four-color jobs, agrees Wills. "As we commonly run one- and two-color work at low resolution," he says, "it's not as big of an issue. However, we feel one- and two-color work is more than a viable option for CTP; it's fast, there are fewer plates and the halftone reproduction is fantastic on marginal paper."
Savings and workflow reduction are certainly important factors in four-color work, agrees Andersen, but, he says, he would not call them dramatic. For example, if you eliminate film and replace it with an expensive proof, how cost-effective is that, he asks. For one-color simple projects, he explains, "You can image a 600 dpi laser paper output DTP via the Opticopy camera cheaper than CTP."