You can use white ink in many useful and creative ways—as a solid area, or as a tint or gradation. The prepress procedures are not complicated, but you must do them in a specific manner to ensure successful printing.
Overview: Preparing files for white ink
Preparing files for white ink requires that you first understand the process, perform prepress preparation, and then set up and save or export the files.
This is the workflow you follow when preparing files for white ink:
1. Understand the four categories of white ink processing.
For details, see below Understanding the four modes of applying white ink.
2. Complete prepress work needed to create white ink data.
The procedure depends on which application you are using. For details, see Prepress procedures for creating white ink data.
3. Prepare files that you want to save or export.
The procedure depends on which application you are using. For details, see Preparing files for saving as PDF.
4. Save the files.
When you set print options for the file, you can also export the file and save it as a preset. For details, see Saving files as PDF.
There are four ways to apply white ink—Spot Color, Underprinting, Overprinting and Duel-View Printing.
Spot Color Mode
Spot color printing is the most straightforward application of white ink. It can be as simple as printing “white only” on a colored, black or clear material. It may also include:
The under-printing method is very similar to spot color printing, but in this application, white ink is used as a “primer” or under-printing on a colored or dark substrate. The color ink is printed on top, providing good color that is not muted by the dark tones of the material below it. This is similar to painting the walls of your home, where a white or off-white primer is sometimes used to cover a dark color that may otherwise “bleed through.” Typical applications include packaging mockups and display pieces where using a dark material is preferred.
The over-printing method is ideal for clear substrates. The graphic image is printed second-surface, mirror-image so that it can be viewed right-reading through the protective surface of the material. Essentially, you’re viewing the design from the “back,” which is why the message must be mirrored. To provide light diffusion and make the color ink more pronounced, the graphic is over-printed with white. Typical applications include backlit panels, diffusion privacy panels and menu boards.
Dual-view printing is a variation on the over-printing method, with one additional step. In this method, a second graphic is also printed, providing a visual that can be viewed from both sides. It may be a duplicate image, or something different such as a decal for a glass door that says “push” on one side and “pull” on the other. The white ink layer is sandwiched between layers of color ink. Typical applications may include two-way decals, static cling labels, day/night signs, door panels and more.