Last month was the first in a series of articles that examines color management from the press all the way back to the monitor and scanner. In the first article we looked at how to profile the press. This month we’ll take a close look at how to take that press profile and make it work with the digital proofer.

One of the biggest bangs for the buck with color management is improved color proofing accuracy. Whether you hang those proofs in the pressroom or print to graybar densities, a colorimetrically accurate proof can save time and money. The days of tweaking color curves or lookup tables at the proofer are over. A spectrophotometer that measures a proof or press sheet can see color much better than our eyes. (Note: If you were unable to profile your press you can always take a standard newsprint profile and load that in your proofing device. Ifra has some very high-quality newsprint profiles that users can download from their Web site at www.ifra.com for evaluation.)



The Compare Tool in GretagMacbeth’s
Profile-Maker Pro allows users to see how
accurate their proof-to-press match is.
Click to enlarge image (37K)

Of course, your proofing device will have to accept International Color Consortium profiles for this exercise to work. If you have any doubts, check with the manufacturer to be sure. Many manufacturers now offer the user the ability to load ICC profiles into their raster image processor. The other important component is proofing on newsprint. This is a nice advantage if your proofing equipment allows you to proof on the actual stock you run on press.

For the best possible results, you’ll need a good description of the press, a good description of the proofer and a good calibration or pre-linearization routine. Although this sounds straightforward, in reality it can be quite complex. If you plan on making the proof profile yourself, you basically want to print a target that captures the full gamut of the proofer in it’s native state. All color correction in the printer driver should be turned off and you should consult with the manufacturer for specific settings when printing the target.

The proofer may have already shipped with a generic profile but it’s been my experience that you get the best results with custom profiles. If you use a third party like ProfileCity (www.profilecity.com), you can get a lot of help. ProfileCity has specific instructions in their knowledge database on how and when to print a pre-linearization or quality analysis target.

Some proofers behave much better than others when it comes to issues like gray balance and the amount of ink they put down for a certain paper stock. If you know your proofer has a good pre-linearization/calibration procedure then you can probably skip the pre-linearization step and go right to profiling the proofer. The pre-linearization step is to ensure that your proofer has been optimized before you profile it.

When you have all the pieces in place you’re ready to see how accurate your proof is. Of course, the output has to check out visually. If your newspaper uses graybars you should compare press sheets printed at proper densities with proofs that were made after calibration. If you don’t use graybars you can check press sheets with proper solid ink densities.

The Compare Tool that is part of GretagMacbeth’s ProfileMaker Pro is one of the most useful tools to check how accurate your proof to press match is. The Compare Tool (at left) allows you to compare the target from your press to the target you print at your proofer. The Compare Tool gives you an average Delta E for the total number of patches on your target. It also shows which color groups need work and which ones are good. A Delta E of 6 is considered a good match in the commercial printing world. Don’t be discouraged if your Delta E is above 6, it just means that something in your chain needs fine-tuning. When all is said and done, a lofty but reachable goal would be an average Delta E of 3.

An accurate proof is critical to color quality that reaches the highest level. Although it takes an investment of time and money, an accurate proof will pay for itself over time. A good color match between proof and press keeps all your internal and external customers happy with fewer complaints and less surprises at the press.

Next month we’ll discuss profiling and calibrating your monitor so that your softproof matches all the other devices in your color-managed chain.

James Kober is the imaging and quality assurance manager at Newsday in Long Island, N.Y. He welcomes your questions and comments on color management, and can be reached jkober@newsday.com.