Colour distortions appearing unexpectedly are never a welcomed surprise. So what is banding and how can you avoid it?
Perhaps you've experienced banding on your own home or office printer. You've got a colourful design or photo ready to print, yet when it comes out you notice odd strips of various shades appearing in your blocks of solid colour.
So what's happening?
Colours bunch together at a low resolution and cause distortions to your file. This undesired (usually) effect makes a non-smooth result and your original design is not correctly/accurately displayed. Various factors can cause banding such as picture format, colour depth, your printer, gradient steps and even the program you're using.
Can it be fixed? Increase the bits!
Steps can be taken to reduce the possibility of banding, but be aware that it may simply be an unfortunate side effect of your chosen means to print. If you're printing your design huge as a poster, the banding may occur but due to the function of the design it'll be virtually unnoticed when viewed from afar as intended.
Before submitting files to print you can check your colour depth to ensure your bits per pixel (BPP) is big enough. 8-bit is more likely to encounter banding compared to a higher resolution such as 24-bit.
Another fix, if appropriate, is to use textures.
We recently received a job for a large movie poster. The scene featured a calm sea, a ship, and a clear blue sky. Due to the style of the design, the setup and the size required, the clear blue sky was subject to some colour banding. The sea came out perfect due to the various water texture throughout, which highlights how the original design could potentially be changed to accommodate their potential banding issues. Applying some faint cloud textures or gradients of a faint sunrise/sunset or perhaps just a clever usage of light sources, all could have achieved a smoother print quality.