File Preparation: About Color Space and Inks Usage

Understanding Color Space and Special Inks Usage

Because RGB color monitors do not accurately represent ink on paper, whether CMYK tints or spot colors, you must reference a printed tint guide before entering values in a color palette. This difference is due to the different methods of producing color (additive on monitors versus reflective in printing) and the differences in the range of color gamuts between the two, as well as differences between actual software applications and general limitations of CMYK printing.

Always verify that placed images have been converted from RGB to Greyscale, CMYK or PMS Spot Color before placing them in your page layout application.

Process vs. Spot Colors

Many desktop publishing applications allow you to specify colors in three ways: You can specify a spot color by product name, such as Pantone; a process color by setting CMYK percentages; and process color tints based on pre-defined systems such as TruMatch and FocolTone. A few things to keep in mind:

1) When specifying both process and spot colors, always work from printed swatchbooks, not what you see on the screen.

2) Be certain to select the right color type - spot or process Pantone - before submitting your electronic file for production.

3) When specifying spot colors, you must be sure to set the process separation button to OFF to ensure that the color you are specifying is not generated as a CMYK process build. This is perhaps the most common error encountered in defining colors on the desktop.

4) Trust the color build representation of our Kodak Approval™ digital color proofs. While the ultimate test is actually placing the job on press, we have spent a great deal of time calibrating our proofing system to our presses and it has proven to be highly reliable.

5) If you're not sure how a process build will look, we recommend that you request a color swatch "scatter proof" Kodak Approval™ before submitting your files for final production.

Four-Color "Rich" Black

Many designs require a four-color or "rich" black for best density. This color should not be defined as 100% each of Cyan, Magenta, Yellow and Black since printing presses cannot deal with this much ink coverage and paper cannot hold this much ink. Your-color black values may need to differ based on the nature of your printing project. Remember that the maximum overall ink coverage for sheetfed offset applications is 300%.

For example, some service providers define warm black as the process color of 0% Cyan, 40% Magenta, 0% Yellow, 100% Black. Likewise, cool black is sometimes defined as 40% Cyan, 0% Magenta, 0% Yellow, 100% Black. If a fuller four-color black is requested, recommend a full "rich" black process build as:

40% Cyan, 30% Magenta, 20% Yellow, 100% Black.

As always, if you're not sure, talk with your Sales Rep about your particular design requirements and expectations. In many cases, such as when photos are placed within a large rich black background, it is appropriate to run an otherwise 4-color job as a 5-color with a second black ink printer in order to control the black dot gain in the photos.

About Special Inks

Metallics, fluorescents and varnishes should each create their own separation. This can be accomplished by applying an appropriately-named spot color to the desired elements in your electronic file. Be aware that the sequence in which ink is applied on press plays an important role in design considerations, particularly with "opaque" Litho White and metallic inks. It's also worth noting that many specialized inks can appear quite different if they are printed on our conventional presses or our UV press or depending upon the particular paper or vinyl substrate that they are being printed on. We highly recommend that you talk to your Sales Rep about the pros and cons of printing with these special inks before committing to your final design.