Editor's note: This is Part 6 of Nate's proofing series.
Well, our prep work is finally complete. Our output device is calibrated and we have an accurate ICC Profile describing how our output device creates color on our selected media, using our selected ink, for our selected workflow.
It's finally time to produce our first color-accurate hard-copy proof. For this final part of our experiment, we will print out of two common applications. This month we will use Adobe Photoshop and next time we'll take aim at Adobe InDesign.
Before we jump right in to the correct Photoshop settings, we need to think about how work actually moves through most workflows. Let's assume that files enter our facility already in a CMYK color space rather than an RGB space. Which space will these files probably be in? In all likelihood, they will have been converted into U.S. Web Coated (SWOP) v2. Why SWOP? Because SWOP v2 is still the default CMYK color space most applications are set to use. And most users don't know, or don't care, to change this setting.
If we are printing these images in our newspaper, we most assuredly are not going to print them to the SWOP standard. SNAP might be an option, although most of our clients will have probably never even heard of this standard.
Could we improve the reproduction of these client-supplied files by converting them to our press profile? The answer is yes, but we probably won't perform this conversion. This reasoning goes back to the time-honored tradition that we never convert client files (unless, of course, they supplied them as RGB files in which case we must convert them) because then we are responsible for the final color reproduction. By not converting, we are sort of passing the color accuracy buck back to the client.
The problem is this: If we use Photoshop for proofing, it will assume that we will convert the file, as that will provide the highest level of color accuracy. Our task then is to somehow fool Photoshop into letting us proof unconverted images.
I'll start by opening the image in Photoshop. It is assumed that my Color Settings are set appropriately and that I have opened the image honoring the SWOP v2 embedded profile. The file is displayed on my color-accurate monitor shown in the indicated SWOP color space (see Figure 1).
Moving to the Custom Proof settings, I have selected my press ICC Profile as my Device to Simulate and have checked the Preserve CMYK Numbers checkbox (see Figure 2). By checking this box I am instructing Photoshop to display the image on-screen in my destination color space as it would appear had I printed the image on that device without actually converting it to that device.
Note that the only Rendering Intent available when this box is checked is Absolute Colorimetric and that this option, along with the Simulate Black Ink and Paper boxes are grayed out.
Accurate soft proofs
Looking at the image on-screen (see Figure 3) we see an accurate soft proof of our unconverted graphic. The problem is that Photoshop assumes that we would never print an image without converting it to our destination space, a step that would result in a much more accurate reproduction of the original image.
Looking at the Print dialog box in Figure 4, you can see that I have selected the Proof option in section A, which will force Photoshop to use my simulation space (the Newsprint Profile) when printing my file. I've told Photoshop to manage the color (section B), selected my laser output device (section C) and in section D told Photoshop to use my Current Custom Proof Setup for image simulation including black ink and paper simulation. The problem is that Photoshop will ignore the fact that I have checked the Preserve CMYK Numbers option in my Proof Setup screen. Photoshop will instead convert my image from SWOP v2 to my newspaper space, and then convert from that space to my laser printer space giving me an image that looks much more like the original but, unfortunately, nothing like what I will see on press.
Little white lie
To overcome this, we have to tell Photoshop a little white lie.
The trick is to assign my final press profile to my image first. Do not convert the image to the final space; assign it (see Figure 5). Converting it is what Photoshop just tried to do when printing the file. With the press, or simulation profile, assigned to the image I can return to the Print dialog screen (see Figure 6).
In the Print dialog screen I can now select the Document option in section A.
Notice that the Document option lists the color space for the image as my newspaper, the assigned profile instead of the true color space, SWOP v2. I'll still let Photoshop manage the color in my document and, in section B will again select my laser printer as my output device and will select Absolute Colorimetric as my desired Rendering Intent. Hitting print and ensuring that all color management is turned off in both my print driver and, if available, on the printer itself will result in the image shown in Figure 7: a true, color-accurate, hard-copy proof.
The only problem with the image I just produced is that it is printed on nice white stock. Newsprint isn't as bright, and the difference between the two can be off-putting to the average client.
Many graphics professionals have resorted to trimming off the white borders before delivering the proof to the client. An easier solution is to proof onto newsprint proofing stock if such a proofing stock is available for your output device. This will, of course, necessitate a new ICC Profile for this media.
I trust that you are starting to get a better idea of how to go about ensuring that your equipment is giving you color-accurate results. It is obviously not a simple task but hey, if it were, where would all the fun and excitement come from? Next time, we'll explore these same color-proofing tasks using InDesign and see if we have to lie to that program, too.
John Nate is a senior color specialist for Chromaticity Inc. He can be reached at 616.988.6119 or firstname.lastname@example.org.