CMYK color mode is a setting in Adobe Photoshop for converting a web-only (RGB) image to be printed. It assigns percentages of each of the four process inks to each pixel. Lighter colors receive smaller percentages of each process color, while darker colors get larger percentages of each.
We ask that all artwork is submitted in a CMYK color mode. To ensure that your artwork converts properly, do all edits in an RGB mode and convert to CMYK color mode as the last step. Any artwork sent to us in an RGB mode will be converted to CMYK, which may affect the final appearance of the print.
Please note that monitors display color as RGB values and should not be used as an accurate representation of how colors will look when printed.