It may sound like I am talking another language but understanding the difference between RGB and CMYK can be very useful. If you want images for the web, it will need to be in RGB, but for print, it will need to be in CMYK or PMS (Pantone Matching System). By selecting the appropriate colour mode can make a massive difference to the precise colour and depth, especially for print. Images sent to print in RGB can appear washed out.
- RGB is short for Red, Green and Blue. All televisions, computer monitors, mobile phones and similar devices display images using RGB output. Graphics designed for this type of media should be done in RGB mode.
- CMYK stands for Cyan, Magenta, Yellow, and Key (black). This colour model is also called “four colour” or “process colour”. Printed items go through the press, which has four plates – one for each colour (C, M, Y, K).
Because of the difference in the two colour models, it is critical that one selects the appropriate mode when starting a new project. If originally designed in RGB, a project can be converted to CMYK, but the colours may not be an exact match from the original selection.
Many graphic design programs like InDesign or QuarkXPress use the CMYK colour model by default. They also have built-in Pantone palettes to allow designers the ability to select an existing PMS colour quickly and easily. This is a technology developed by Pantone that allows designers and printers to achieve colours not able to be mixed through CMYK. Also, it is not an everyday process or use of software that many people may use or have available to them on a day to day basis unless they are in the industry.
One important thing to remember is that PMS and CMYK colours do not view “true” on a computer monitor because a monitor is RGB. There are Pantone swatches and chip books available for both graphic designers and printers to view the colour on coated or uncoated stock as again the colours can be very different. This makes colour selection much easier than trying to pick based on what you see on the computer screen.
On large print jobs, the designers will always agree on the colour with the client and by getting signed off printed proof of all the printed items before sending the job to press. This will give the designer and client the opportunity to review the colours and confirm they are correct before the project does a full print run.
The main thing to remember is RGB for digital and CMYK for Print.