RGB Must be Converted to CMYK Color in Order to Print
At some stage your RGB file must be translated to CMYK in order to print it on a printing press. It is best if you do the RGB to CMYK Conversion of your images. You will have more control over the appearance of your printed piece if you convert all of the images from RGB to CMYK before sending them to us. Be aware that it is possible to create colors in RGB that you cannot reproduce with CMYK. These are beyond the CMYK color range or "out of the CMYK color gamut".
Here are some examples of how various RGB colors convert to CMYK:
RGB Colors (what you see on screen)
CMYK Colors (printing inks will do this)
You most likely won't notice this kind of color shift in a color photograph. It is more likely to happen if you pick a very rich, vibrant color for a background or some other element of your layout. It probably won't look bad, it just won't look exactly the same. But it may not be noticeable at all either.
To purchase a color guide with thousands of process colors with their RGB values and their CMYK screen percentages, please visit Pantone <link to Pantone here> to purchase swatch book. We recommend the PANTONE Color Bridge Set which contains both coated and uncoated stock ink swatches.
When we receive RGB images in a job we instruct our RIP software to make the conversion to CMYK. The RGB to CMYK conversion table tries to map colors to get as close as possible to the appearance of the original. We think that it does a very good job but it is possible that it might not be to your liking.
Here is an example: many programs translate the 100% Blue in RGB into a purplish blue color in CMYK (Adobe InDesign CS2 will give you C88, M76, Y0, K0). We suggest that you use a CMYK value of C100, M60, Y0, K0 to get a nice blue. Working in the CMYK color space allows you to select the exact CMYK mix that gives you the results you want.
We want you to be pleased with your job, so please, take the time to prepare your file properly. We cannot be responsible for results if you furnish your images in RGB. Even though monitors always use RGB to display colors, the colors you see on your monitor will more closely match the final printed piece if you are viewing them in the CMYK color space.