What is banding and how can I prevent it
Banding appears as visible lines or stripes in gradient areas of a printed piece. It happens when a gradient transitions too quickly — for example, going from a very light color to a very dark color across a small area, leaving visible steps instead of a smooth blend.
Banding can also be caused by how your file is exported from programs like InDesign or CorelDRAW.
To prevent banding, give your gradients enough physical space for a smooth transition. Check your digital files before sending — if you can see any stepping or banding on screen, it will be visible in print. Adding a small amount of noise (1-2%) to gradient areas in Photoshop can also help smooth out transitions.