Print gradients, meshes, and color blends

Files with gradients, meshes, or color blends can be difficult for some printers to print smoothly (without discrete bands of color) or at all.

Files with gradients, meshes, or color blends can be difficult for some printers to print smoothly (without discrete bands of color) or at all. Follow these general guidelines to improve the printed results:

• Use a blend that changes at least 50% between two or more process-color components.

• Use shorter blends. The optimum length depends on the colors in your blend, but try to keep blends shorter than 7.5 inches.

• Use lighter colors, or make dark blends short. Banding is most likely to occur between very dark colors and white.

• Use an appropriate line screen that retains 256 levels of gray.

• If you create a gradient between two or more spot colors, assign different screen angles to the spot colors when you create color separations. If you’re not sure what the angles should be, consult your print shop.

• Print to an output device that supports PostScript® Language Level 3 whenever possible.

• If you have to print to an output device that supports Postscript Language Level 2, or when printing meshes that include transparency, you can choose to rasterize gradients and meshes during printing. As a result, Illustrator converts gradients and meshes from vector objects to JPEG images.

When printing your file, you may find that the resolution of your printer, when combined with the chosen screen frequency, allows fewer than 256 levels of gray. A higher screen frequency decreases the levels of gray available to the printer. For example, if you are printing at a resolution of 2400 dpi, using a line screen higher than 150 results in fewer than 256 levels of gray. The following table lists the maximum line-screen setting you can use with printers to maintain all 256 levels of gray:

Illustrator calculates the number of steps in a gradient based on the percentage of change between the colors in the gradient. The number of steps, in turn, determines the maximum length of the blend before banding occurs.