Production tips for preparing Blends
Blends: Blends (also referred to as vignettes or gradients) are best created in applications such as Photoshop or Illustrator, then imported into the page layout application. Imported graphic files that contain a large number of blends are likely to cause production delays. Blends created directly in the page layout software should be tested first to ensure their quality.
To avoid banding in your blends, keep the following rules in mind:
Blends that extend a greater distance have a higher potential for banding.
Higher resolutions can help reduce banding.
A gradation from a 30% to 40% tint will be more likely to show banding than one from 1% to 100% over the same length. Limiting the range of the blend also limits the number of shades available.
Never attempt a blend from one spot color into another spot color or from a spot color to a process color. These blends are extremely difficult to trap. Always blend CMYK combinations, or blend one spot color to a lighter tint of the same spot color.
When creating a blend of a spot color to white, specify 0% of the spot color on the lighter end of the blend. Using white changes the spot color to its simulated four-color process equivalent.
When generating a blend in Photoshop, add noise (amount = 2 or 3) to the vignette. This will help break up any banding.