For the past year, these articles have concentrated on color management fundamentals and color management issues that were centered about Adobe Photoshop.

Although a large portion of the color management tasks performed in our industry are done within Photoshop, it is important to understand what happens within other color applications we may use.

Case in point: PDF workflows. As more graphic artists adopt PDF, it’s imperative we understand how to set up Adobe Acrobat and Adobe Acrobat Distiller.

Myriad options in these two packages allow the casual user to implement a workflow that will automatically screw up any image they process.

In this article, I will be providing you with an overview of settings that can be used in several different workflow scenarios. Because of the depth of these two programs, covering all of the possible settings is far beyond the scope of this article (I’ll leave that to the book writers). Instead, we’ll cover some of the more important settings.

The following are recommended settings for use in the preparation and printing of PDF files using Distiller and Acrobat, respectively.

Remember that each of these programs has a large variety of variables that could impact the settings required and also the results obtained. So be warned and be prepared to test these settings in your own workflow.

Adobe Acrobat Distiller

The first group of settings (Figure 1) is used to prepare PDF files that would be used in a simple prepress workflow. Here, color management has been turned off and all images will simply pass through Distiller unaltered.

Fig. 1: The first group of settings in Adobe Acrobat Distiller is used to prepare PDF files that would be used in a simple prepress workflow.

These settings are used when all of the images in the document have already been converted to the proper CMYK space required for accurate reproduction. These images could also be proofed properly if the resulting files were sent to a proofing process set to simulate your press. It is assumed that these files would not be repurposed. All colors in the file are the same as they were when the PostScript source file was produced.  Additionally, none of the images will be tagged with profiles.

With no source profile embedded, soft proofing and remote proofing will be difficult unless a color-managed RIP is involved in the process. In a traditional prepress proofing workflow this will not be a problem.

Look at the bottom area of this dialog box. Here you need to set the rules and regulations concerning gray component replacement, under color replacement, transfer functions and halftone information.

How you set these options depends upon the rest of your workflow. If GCR and UCR have been applied to the images, and these settings are also part of the PostScript file, you will want to uncheck this box. Transfer functions, often used to adjust for dot gain, and specific halftone screen specifications are commonly set to be either removed or ignored.  

If repurposing (one of the major benefits of a digital workflow) is an issue, things can get a bit more complicated. Let’s assume that the file has been prepared just like it was in the previous example, with all conversions being done before the PostScript file was generated.

Because this file is properly prepared for output, a single output profile can be used for the file. By selecting “Tag Everything for Color Mgmt (no conversion)” (Figure 2) the profiles listed in the Working Spaces portion of the panel will be embedded into the resulting PDF file and will automatically be used by Acrobat and Acrobat Reader to produce a soft proof.

Fig. 2: By selecting “Tag Everything for Color Mgmt (no conversion)” the profiles listed in the Working Spaces portion of the panel will be embedded into the resulting PDF file and automatically used to produce a soft proof.

If the RIP used in the workflow can read color-managed PDF files with embedded profiles, the PDF file can then be repurposed accurately.

Keep in mind that these settings still do not convert any of the images in the PostScript file. It is assumed that this was done properly when the PostScript file was generated, before the PDF file is made. Because the images in the file are assumed to be in a CMYK colorspace, relative colorimetric is probably the most accurate rendering intent (see Newspapers & Technology, March and April 2004, for more information on rendering intents).

The problem with the above settings is that if the resulting PDF file is repurposed, black objects such as black text will be color managed and will probably be converted to a rich black.  If you select “Tag Only Images for Color Mgmt (no conversion)” (Figure 3) instead of “Tag Everything for Color Mgmt (no conversion)” black text will remain black.

Fig. 3: When “Tag Only Images for Color Mgmt (no conversion)” is selected, black text will remain black.

The downside of this is that spot colors may no longer be accurately reproduced.

Adobe Acrobat and Acrobat Reader

If a PDF file is opened into Adobe Acrobat or Acrobat Reader and then printed from that application, consider setting the color management preferences to those traditionally recommended in most Adobe products (Figure 4). This will provide an accurate soft proof, and if any files are received that do not have the working space profiles embedded, they will be automatically applied on-the-fly as the data moves to the monitor.

Fig. 4: When printing a PDF file from Adobe Acrobat or Acrobat Reader, consider setting the color management preferences to those traditionally recommended in most Adobe products.

When printing to a PostScript printer from Acrobat or Acrobat Reader, selecting File>Print and then clicking on the “Advanced” button will reveal the dialog box seen in Figure 5.

Fig. 5: The dialog box that appears when printing to a PostScript printer from Acrobat or Acrobat Reader, selecting File>Print and then clicking on the “Advanced” button.

Selecting the “Apply Working Color Spaces” checkbox will apply the working spaces selected in the previous preferences window to any untagged images. If the file has been prepared as directed in the first example listed in this article, this should not be necessary.

Setting the Color Profile to “Same As Source” will ensure that Acrobat passes the data to the printer with no color conversion, rendering Acrobat color neutral in this particular workflow.

Obviously, there are many variables to the PDF workflow and I have only scratched the surface here. Feel free to vary any of these settings to determine if it increases the quality of the output in your particular workflow. As with all things related to color management, testing and evaluating are the keys to success.

John Nate is a senior color specialist for Chromaticity Inc., an integrator of color technologies for the newspaper and other industries. Nate can be reached at 616.361.7773 or via e-mail at jnate@chromaticity.com.