Product

Platform

Server: Dell or Data General all; Client: PC or Macintosh

Operating system

Server: Windows NT or 2000; Client: Windows or Macintosh

Error

Symptoms

I need to produce grayscale output from colored pages.

Producing grayscale output from colored pages may be required in some circumstances:

1. A job is prepared in 1-color, but there are colored elements in the pages (for example, clipart or screenshots).

2. A job is prepared in color but, at the time of printing, is changed to be printed in black (K) only.

3. A color job is needed to image to grayscale film for blueline.

Cause

Solution

There are three ways to produce grayscale output in Prinergy:

1. Convert to grayscale at refine and run grayscale all the way through the workflow.

2. Select grayscale at output for 300, 600, or 2400 dpi.

3. Use color mapping to map process colors to "dummy spot colors".

Option 1 is useful when you know that the destination press is black and white. For example, when converting RGB screen captures to B&W for a manual.

Option 2 is useful when producing digital bluelines (image quality may not be very good).

Option 3 is useful when you do not have Advanced Color Management, but only Basic Color Management.

Option 1 Procedure, Refining to Grayscale:

When you refine using this process plan, all RGB and CMYK images and graphics including spot colors are converted to grayscale.

1. In the Refine Process Plan, ensure that the Colorconvert process is enabled, then enable all the default input ICC profiles (CMYK image and graphics, RGB image and graphics). User-defined input ICC profiles are also acceptable.

2. For the destination, or final profile, there are some default gray ouptut profiles in the ...\Prinergy2.0.4\CreoAraxi\data\ICC-Profiles\gray directory, eg.GrayFromK-SWOP-Adobe-Percep.icc.

- If their press space is SWOP and they used Adobe' USWebCoatedSWOP.icc, for the 1st refine

then customers should set GrayFromK-SWOP-Adobe-Percep.icc.

- If their press space is SWOP they used PO_SWOP_CGATS_TR001 U300K95.icm for the 1st refine then GrayFromK-SWOP-HDAG-Percep.icc is recommended. If pure black objects are getting converted to a tint, try using Relative Colorimetric rendering intent and the associate profile (for example, GrayFromK-SWOP-Adobe-Relative.icc).

You may also use your own gray profile if you have one. However, make sure that it is a device profile and not a devicelink profile. This sets up the conversion to grayscale.

3. Select Set Colors to Knockout and set Black to Overprint. This ensures that all colors are converted, as the Colormatcher does not operate on overprinted colors, and that pure black will be untouched and passed straight through.

4. Set Map Spot Colors to All to Process.

The main limitation of this procedure is that only composite files can be run through this process. However, once it is set up, output is produced quickly and easily.

Note: For current versions of the Creo and HDAG Colormatcher, CMYK (0,0,0,100), RGB (0,0,0), and DeviceGray (0) gets correctly transformed into 100% black in grayscale.

For the HDAG CM, this procedure works on RGB pages with Basic Color Management. However, since most pages contain at least some components of CMYK in practice, this feature requires the Advanced Color Management option. For Creo's CM, this will work with only Basic licensing no matter what the input colorspace.

Option 2 Procedure, Convert to Grayscale at Output:

This can be used for any type of file (composite and separated), but slows down output a bit.

1. In the Render section of the Output Process Plan, select DeviceGray as the process color model, and turn Shades to 1. Note that this choice is only available from a few of the output types (TIFF, EPS). This is not available for direct imaging to the device.

2. To get acceptable output, set the output process plan's ColorConvert Proof Process Profile to gray/GenericGray.icm and Assume Proofer Resembles Final Paper. (Note that this requires Advanced Color Management.)

3. In the Render section, set Spot Color Handling to Convert to Process.

Note: There are two restrictions for RIPing colored pages to screened grayscale:

- This is only possible with a TIFF connection to the device.

- Regardless of process plan settings, screening information will always be overridden to Round dotshape at 175 LPI.

Option 3 Procedure, Using Color Mapping:

1. Create some spot colors in the ColorEditor. For example: “30Black�, with a recipe of 30% black, “50Black� is 50% black, and “70Black� is 70% black.

2. During refining, map Yellow to “30Black�, Cyan to “50Black�, and Magenta to “70Black�.

3. At output, convert all colors to process.

This solution allows you to manually convert CMYK to black only on output, without the need for Advanced Color Management.

Permanent fix:

See also

Keywords

color, output

Technical contact(s)

Ken Lew

Submitted by

James Bredenhof

Date submitted

14 Mar 2000