Why do certain colours look different after they print?

There are a number of reasons your printed product may not match the design from your computer.

RGB vs CMYK #

Ever noticed that your printed colours don’t look quite like they do on your computer screen? That’s because screens and printers use different colour models, called RGB and CMYK. This article will help you understand the difference between these colour models, why they affect how colours appear, and what you can do to get the most accurate print results.

Colours Look Different in Print vs. On-Screen #

This is usually due to the difference between RGB (screen) and CMYK (print) colours. We have systems and processes to match colours but beware that some colours you may have seen on your screen may not possible to print in a CMYK printing process.

What Are RGB and CMYK? #

• RGB: RGB stands for Red, Green, and Blue. This colour model is used for screens, such as computer monitors, TVs, and phone displays. It creates colour by combining red, green, and blue light at varying intensities. Screens are able to display bright and vivid colours because of the additive nature of RGB, where adding all colours together produces white light.
• CMYK: CMYK stands for Cyan, Magenta, Yellow, and Key (Black). This model is used for printed materials. Instead of light, CMYK combines physical ink colours, using layers of cyan, magenta, yellow, and black ink to produce various shades. Unlike RGB, CMYK is a subtractive model—combining all the colours produces a darker, near-black shade rather than white.

Why RGB and CMYK Colours Differ #

The primary reason RGB and CMYK produce different results is due to the way each colour model creates colours:

• Brightness and Vividness: RGB is often more vibrant and can display a wider range of bright colours (especially neons and high-saturation hues) that CMYK simply can’t replicate.
• Colour Range (Gamut): RGB has a broader colour range than CMYK. Some colours you see on your screen, especially highly saturated or luminous tones, don’t have direct counterparts in the CMYK model. This means that, during printing, certain RGB colours are approximated, often resulting in a less vivid print.

Common Issues with RGB-to-CMYK Conversion #

Here are some common challenges people face when converting RGB files to CMYK for print:

• Dull or Muted Colours: Bright colours like neon greens, intense blues, and certain pinks and purples tend to lose their brightness when converted to CMYK. This happens because the inks can’t recreate the same vividness as RGB light.
• Colour Shifts: Sometimes colours in RGB files appear noticeably different when converted to CMYK. For example, certain blues may shift to more purple or greenish tones, depending on how they interact with the CMYK inks.
• Contrast and Depth Differences: RGB often allows for greater contrast and depth, especially with dark colours. In CMYK, these colours may print with less intensity and depth, as the inks create layers that absorb light differently than screens emit it.

How to Prepare Your Files for Accurate Colours #

For the most consistent print results, you can take a few steps to prepare your files:

• Use CMYK-Safe Colours: Avoid extremely bright or neon colours, as these are difficult to replicate in CMYK. Choose colours with slightly lower saturation and brightness to achieve a closer match.
• Proofing: Use a soft-proofing feature (available in many design software programs) to preview how your design will look in CMYK. For critical colours, consider placing a small order to verify the final appearance before mass production.
• Avoid Heavy RGB Effects: Effects like strong glows or gradients can look vibrant in RGB but may lose impact when printed. Adjust effects for clarity in CMYK mode.
• Check Your Monitor Calibration: If your monitor isn’t calibrated, colours on screen may appear differently than intended, even in RGB. Calibration helps you see a closer representation of how colours will print.

Prints on Dark Coloured Products #

Printing on a coloured product backing (especially dark-coloured) can significantly alter the way colours appear in the final print. This is especially true for lighter colours and designs with subtle details, which may not show up as expected on dark surfaces. We print with a white base layer wherever possible to alleviate this problem but the below information can still help.

How Dark-Coloured Backing Affects Colours #

• Absorption of Light: Dark colours absorb more light than lighter colours, making lighter inks appear less vibrant and sometimes harder to see. This is why printing on black, navy, or dark grey may reduce the brightness and clarity of colours compared to a white or light background.
• Ink Transparency: Most printing inks are slightly transparent, allowing the background colour to show through. On dark backings, this transparency can make colours appear darker or even change their hue. For example, a bright red printed on a black surface may appear dull or muddy.

Common Challenges When Printing on Dark Surfaces #

Here are a few specific issues that often arise when printing on dark-coloured backing:

• Faded Colours: Lighter colours, such as pastels or bright tones, may appear faded or lose contrast against dark backgrounds.
• Colour Shifts: Some colours may shift or blend with the dark backing, making them appear slightly different from the original design.
• Detail Loss: Fine details, especially in light colours, may be less visible on dark backings. Small text or thin lines can be difficult to read or may blend into the background.

Preparing Your Design for Dark Backgrounds #

To ensure the best results when printing on dark surfaces, you can take a few steps in the design phase:

• Choose Bolder Colours: Darker backgrounds tend to dull colours, so choosing more saturated, vibrant colours can help maintain contrast. Avoid very light or pastel colours unless you’re using a white ink base.
• Adjust for Higher Contrast: Design with high-contrast colours that stand out against dark backings. Rich colours like bright yellows, oranges, or vibrant reds tend to be more visible and retain their impact on dark surfaces.
• Limit Fine Details: Avoid using thin lines, small text, or intricate patterns in light colours, as these may be difficult to see on dark backings. If necessary, increase the thickness of these elements to enhance visibility.