Understanding color systems is vital when you want your packaging design to look good in real life as it does on a computer screen.
Although you can give this task to your graphic designer and print manufacturer, knowing the industry’s standards for color can aid your selection process and level expectations about the printing outcome.
This article is primarily about CMYK, but we’ll also touch on the other two most prominently used color modes in the design world—RGB and Pantone. Color models are the building blocks that represent an image and have their own gamut or color ranges. They achieve unique levels of color detail according to their number of channels or colors. Their comparison can deepen your appreciation of CMYK as the most effective color model for printing.
CMYK stands for the four ink colors used in printing—cyan, magenta, yellow, and black. The CMYK system blends these colors to create about 16,000 variations. In the color wheel:
- Cyan falls between blue and green, but most people see it more as the former color. It’s similar to sky blue or the aqua blue color seen in tropical ocean waters.
- Magenta falls between red and blue, but most consider the color closer to red instead of blue. It’s comparable to fuchsia and hot or deep pink. People associate this color with bougainvillea flowers and orchids.
- Yellow is the lemon yellow, canary yellow, and gold hues we see in nature, such as sunflowers, daffodils, and sunshine.
- Black is the color of coal, volcanic rock, and some gemstones like obsidian and onyx. The other meaning of “K” is “key” because the black ink plate provides fine details, depth, and contrast in the resulting image. Thus, “key plate” is the other term referring to the black plate.
In theory, mixing cyan, magenta, and yellow results in black. In reality, however, their combination results in a muddy dark gray. Moreover, a 100% three-color blend soaks the paper in ink, slowing down the drying process.
How Does CMYK Work?
Each CMYK ink color has a separate printing plate, and the ink transfers or offsets from this plate onto a rubber blanket and then on paper as tiny dots. The colors become solid and continuous as the dots overlap until the four-color process or process printing is complete.
Meanwhile, digital printing doesn’t require color separation. The ink goes directly onto paper instead of plates, making them a cost-effective option if you have a lower quantity printing order.
The printer copies the image from your file. From there, individual CMYK color droplets produce the illusion of a colored image. Inkjet printers use ink while laser printers—used in commercial applications—use toner.
RGB and Pantone Systems
To improve our understanding of CMYK, we must compare it with the RGB and Pantone color models.
Graphic and packaging designers refer to RGB—red, green, blue—as desktop colors because they represent the colored lights used on electronic displays (computer monitors, mobile devices, TV sets, and digital cameras), whether it’s for videos, websites, and apps.
Moreover, this color model offers the most expansive range of colors—16.7 million in all. As a result, discrepancies occur between colors on screen and print, as CMYK has a narrower color gamut.
RGB vs. CMYK: Additive vs. subtractive color models
When comparing RGB and CMYK, it’s important to know that RGB is an additive color model, while CMYK is a subtractive color model.
RGB is an additive color model that combines various intensities of red, green, and blue light to produce other colors. You get pure white when you mix RGB colors at their maximum brilliance. Meanwhile, you must combine the three colors at their lowest intensity (minimal light) to produce black.
The opposite happens with CMYK, a subtractive color model. Unlike electronic screens, paper isn’t transparent and doesn’t allow light to pass through. One must apply less color to see white. Images appear with a lighter tone when paper receives fewer ink dots.
Because CMYK inks only reflect light—unlike RGB colors that emit them—it’s best to convert RGB images to CMYK for accurate printing.
The Pantone Matching System (PMS) follows a numbering system for accurately and quickly identifying colors for printed materials, fabrics, and paints. Every Pantone color—2,161 of them—has a unique code corresponding to a pre-mixed ink formula, aiming to produce the colors consistently across different projects. These colors include fluorescent and metallic colors, which aren’t available in the CMYK and RGB models.
When you ask a professional printer to match your specific PMS colors, its staff adjusts the digital printer’s colors until the result matches your PMS swatch.
Spot or solid color is another name for the color printed on paper using premixed ink to match a PMS, unlike the CMYK process, which involves four layers (one for each color). In effect, the blending of colors happens before and not during printing for spot colors.
Spot colors consist of a name or number and end with either a C (coated) or U (uncoated), referring to the paper stock type on which to print it.
When to Use CMYK and Spot Color Printing
Here are some tips to help you determine when to use the four-color or spot-color printing technique:
CMYK or process printing is ideal for projects involving so many colors that using several spot inks would be impractical and expensive. Examples include full-color photographs, paintings, and very complex colored images.
CMYK—the most widely used standard digital and offset printing system—is also cost-effective for low-quantity orders with multiple hues and gradients. However, color-matching won’t be as precise as spot colors. Some printers offer a broader range—also referred to as extended or expanded color gamut—that includes orange, green, and violet to improve brightness and realism.
You can use spot color printing for jobs requiring a few (one or two) exact colors, such as your brand colors and business logo, and colors outside CMYK’s color range—pastels, metallics, and fluorescents. Spot colors would cost you more per order because they require ink colors with specific formulations and a separate plate.
CMYK and Spot Printing
You can use both techniques simultaneously when, for instance, you must print an image (CMYK printing) and your company logo or product name (spot color) close to each other. Another example is when you want to increase the intensity of a specific process color or coat portions of a full-color image with a clear varnish, which is a spot color.
Below is a quick reference of the three color models—their characteristics and uses:
|Color Gamut or Range
|Used for Printing?
|Color layers printed in succession on packaging material
|Full-color images (photograph, painting, complicated images)
|Color pixels arranged to produce new colors on digital screen
|Websites, apps, videos
|Pre-mixed, solid color ink applied directly on packaging material
|One to two critical colors (logo, company colors)
Tips for Improving Color Accuracy When Previewing CMYK Colors on Your Screen
Because RGB can display more colors than CMYK, the way you see a design or image on the screen may not be accurately reproduced through the CMYK print process.
But you can reduce the discrepancy between the two by following these tips:
1. Calibrate your monitor and perform soft proofing
PC and laptop manufacturers gear factory settings toward film viewers and gaming fans, resulting in high brightness, high contrast, and saturated colors.
Thus, recalibration is necessary when working on packaging designs. Adjust your device’s color settings (“color profiles” on Mac) to match your color standard, particularly the brightness or luminance of your display. Your printouts may appear dark if you’ve been designing and editing on a very bright monitor. Most monitors have built-in calibration tools
D50 is the recommended white point or white balance for LCD monitors when working with still images. White point is the temperature setting that determines the coolness or warmth of your whites.
2. Perform soft proofing
Check your software’s color management system. Adobe Photoshop and Illustrator’s soft proofing feature lets you view your artwork the way it will appear on a surface when printed by the CMYK method.
3. Refer to color swatches and guides
Printed samples of colors are a handy reference when checking designs and images on screen and paper.