RGB versus CMYK

RGB and CMYK are two color models commonly used in the world of digital and print design. RGB and CMYK have distinct purposes and charac­te­ristics, and knowing when and how to use them appropriately is essential to ensure accurate color representation in different media.
First of all, let's familiarize ourselves with the specific terms:

Color Models: Color models define how colors are created and represented digitally. They describe the mathematical calculations and combinations of primary colors used to generate a wide range of colors. Examples of color models include RGB (red, green, blue) and CMYK (cyan, magenta, yellow, and black). You can compare them with the basic colors you use in the physical environment, namely red, yellow and blue.

Color profiles: Color profiles are standardized sets of instructions that ensure consistent color reproduction across different devices or media. They contain information about color space, gamma correction, white point, and other characteristics specific to a particular device or media. Color profiles help maintain color accuracy and consistency.

Color gamut: Color gamut refers to the color spaces that can be represented in a given color model. For example, CMYK has a narrower space than Pantone, which is narrower than RGB, but which in turn is narrower than visible space.

These terms are essential to understand when working with color in digital and print design, as they help ensure accurate color reproduction and uniform color appearance across different devices and media.

What is RGB?

RGB is an acronym for red, green and blue. It is an additive color model that reproduces a wide range of colors by combining different intensities of red, green and blue light. For example, if you mix red and green light, you get yellow; if you mix blue and green light, you get cyan; and if you mix all three colors, you get white.
RGB is commonly used in digital devices such as computer monitors, televisions, cameras, scanners, printers, etc. to display the colors on the screen. Each color channel (red, green, and blue) is represented by a number from 0 to 255, where 0 means no light and 255 means full light.
For example, the RGB code for pure red is (255, 0, 0), for pure green is (0, 255, 0) and for pure blue is (0, 0, 255) By adjusting the intensity of each component, different colors can be obtained .

When to use RGB?
You should use RGB when designing anything that will be viewed on a screen, such as websites, apps, digital design, social media, or online advertising. RGB is the right color mode to use for digital designs because it offers a wider range of colors than CMYK. RGB is also used in digital cameras, scanners, and other digital image display applications.

What happens when you print?
In general, if you try to print an RGB image, the colors may not match what you see on the screen because the printer has to convert RGB values to CMYK values. There are special printing equipment that work with RGB files, having their own software that converts and adjusts the colors from RGB to CMYK, so that the printed result matches the digital image. However, if your print supplier does not have such equipment, you should always convert your RGB images to CMYK before sending them to print.
At Printoteca, both textile print technology and fine art prints are based on RGB files.

What are the best file formats for RGB?
The best file formats for RGB depend on the purpose and quality of your images. Some common file formats for RGB include:
JPEG or JPG: This is a widely used format that compresses the image to reduce file size, but can also reduce quality. JPEG is good for photos and images with many colors, but not for text, logos or graphics with sharp edges.
PSD: This is the standard source file format for Adobe Photoshop, which preserves all the layers, effects, and settings of your image. PSD is good for editing and storing original images, but not for sharing or displaying them on the web.
PNG: This is a lossless format that preserves the quality and transparency of your image, but can also result in a larger file size. PNG is good for graphics, icons, logos, text or images with transparent backgrounds.
SVG: This is a vector format that uses XML code to define the shapes, colors and paths of your image. SVG is good for scalable graphics, icons, diagrams or user interface elements.
GIF: This is a format that supports animation and transparency, but only allows 256 colors. GIF is good for simple animations or images with few colors, but not for photos or complex graphics.

What is CMYK?

CMYK is a color model that is used in color printing. This represents Cyan, Magenta, Yellow, and Black, which are the four ink colors used to print images on paper. CMYK is a subtractive color model, meaning that colors are created by subtracting light from a white background. The more ink you add, the darker the color becomes.

CMYK color
CMYK is different from RGB, which is an additive color model used for screen display. RGB uses red, green and blue light to create colors by adding them together. The more light you add, the brighter the color becomes. RGB has a wider color gamut than CMYK, so some colors you see on screen may not be exactly reproduced on paper. Therefore, if the print supplier does not have equipment that uses RGB files, you must convert the images from RGB to CMYK before sending them to print.
CMYK colors are defined by percentages of each ink color, from 0% to 100%. For example, Pure Cyan is 100% Cyan and 0% Magenta, Yellow, and Black. Pure black is 0% cyan, magenta and yellow and 100% black.

When to use CMYK
You should use CMYK when working with printed materials such as business cards, flyers, posters, magazines, books, packaging, etc. CMYK is the color model that printers use to reproduce colors on paper by mixing cyan, magenta, yellow and black. inks.

What are the best file formats for CMYK?
The best file formats for CMYK depend on the type and quality of your print project. Some common file formats for CMYK include:
PDF: This is a widely used format that preserves the layout, fonts, graphics and colors of the document. PDF is compatible with most programs and printers and can handle both vector and raster images. PDF is good for brochures, flyers, posters, magazines, books, etc.
AI: This is the standard source file format for Adobe Illustrator, which is a vector-based software. AI preserves all the layers, effects and settings of your image and lets you edit them later. AI is good for logos, icons, illustrations or graphics that need to be scaled without losing quality. Don't forget to convert fonts to curves, embed images and expand shapes.
EPS: This is a similar format to AI, but is compatible with other vector programs besides Illustrator. EPS also preserves the vector information of your image and can be edited or scaled as needed.
TIFF: This is a lossless format that preserves the quality and detail of your raster image, but can also result in a large file size. TIFF can handle CMYK colors and transparency and can be compressed without losing data. TIFF is good for photos, images with gradients or shadows, or complex graphics.

What is the difference between RGB and CMYK?
RGB and CMYK are two color modes used by graphic designers for different purposes. RGB stands for Red-Green-Blue and is best for digital images that will be displayed on a screen such as a computer, TV, tablet or smartphone. CMYK stands for Cyan-Magenta-Yellow-Black and is ideal for designs that will be printed with ink, such as brochures, flyers or business cards.
The main difference between RGB and CMYK is that RGB is an additive color model, meaning that the more color you add, the lighter the result. For example, when you mix red, green and blue light, you get white light. RGB has a numerical range of 3x256, meaning there are 256 levels of each of the three colors that can be combined to create over 16 million colors.
CMYK, on the other hand, is a subtractive color model, meaning that the more color you add, the darker the result. For example, when you mix cyan, magenta, yellow, and black ink, you get black ink. CMYK has a numerical gamut of 4x100, meaning there are 100 levels of each of the four colors that can be combined to create a smaller color gamut than RGB.
Choosing the right color mode for your design project is important because it affects how the final design will look. If you use RGB for a design that will be printed, the colors may appear duller or different than what you see

on display. If you use CMYK for a design that will be displayed on a screen, the colors may appear muted or distorted. Therefore, it is best to use RGB for digital designs and CMYK for printed designs.

Can RGB images be printed?
Standard printers use CMYK inks, so in most situations they need CMYK files for printing. As the screen will render the file in RGB mode, allow for differences between the digital and printed product, so it is essential to sample before a larger project and adjust the file until you get the best printed result.
When you print an RGB image directly, the printer must convert the RGB values to CMYK values, which can result in color shifts or loss of quality. Some RGB colors are outside the CMYK color gamut, so they cannot be reproduced exactly on paper.
For example, bright neon colors or deep blues may appear duller or darker when printed.
Some printers have their own software that converts RGB to CMYK and also have extra color ink cartridges to reproduce as much of the RGB space as possible. At Printoteca, for example, the Kornit equipment for textiles has 6 colors, and the Epson printer for Fine Art has 12 colors.