New Thoughts on RGB and CMYK
Traditionally, printers have encouraged customers to supply CMYK-ready image files with their layouts or as images embedded in PDFs. With the wide range of digital and conventional presses in use today, and the limitations of the default settings with which Photoshop is configured, we've decided to expand your options.
To take a step back, almost all digital camera or stock photo images are initially stored in the RGB color space, yet at some point must be converted to CMYK to print. We find that when the image is converted using our own expertise and proofing systems, the color quality may exceed that of a one-size-fits-all default setting in Photoshop. This is a result of both staff expertise and conversions specific to the devices and processes we use to print your job.
A gamut describes the range of different colors that can be seen or reproduced. Notice the difference between offset printing's CMYK gamut compared to the gamut of a typical RGB monitor.
If you plan on converting RGB to CMYK yourself, here are the Photoshop settings we recommend:
When RGB images are converted to CMYK, there is some color shift to keep the image within a range of what is printable on press. The conversion to the smaller CMYK space tends to impact deep blues and greens hardest. The ink, the paper's brightness, and a number of press characteristics determine the actual range of color that we will be able to achieve.
Another option is for you to rely on our experts to do your conversions for you. With this "critical color" approach, just supply us with RGB images and our experts will convert and color-correct your images for you, with the proofing resources we need to confirm our edits. It's a modest-cost approach to getting the best color possible.