Certain high-volume digital printing presses can be equipped to print opaque white ink.  For the first time, new possibilities to design around colored paper stocks has become a reality.  The first thing designers think of is “Awesome, now I can print images on cool papers from Neenah, Mohowk, Reich and French paper!”.  The second thing they think of is “How do I set up my InDesign files?”.

Warning!  Before you specify that beautiful paper stock you love, check with your print supplier to make sure they can/will print on that stock.  Most printers want to print only on certified digital papers, ones certified to adhere and run smoothly on the digital press. The problem is that digital stocks are a bit limited in number.  The good news is that some printers will work with you to test a particular stock.

Preparing your files (InDesign)

First, you’ll need to create a Spot Color swatch in your palette called White. Select the Color Type as Spot while leaving the Color Mode as CMYK. You should give it a bit of color (say, 15% Cyan) so you can see it in your design.

Assign the color White to all parts of your art that you wish to print in white ink. In this picture, you see that the text and images at top have been set to print white.

If you wish to have white ink print under the CMYK, your White areas need to be
placed on top of the CMYK areas and be set to overprint. In the picture below,
you can see that we have a White area for the flowers overlaid on the image
and in the upper left corner, it shows we have set the Attributes to Overprint Fill.

When you generate your Press Quality PDF and view using the Output Preview feature,
you should have an additional Spot Color separation called White. The top picture
shows the CMYK portion of your image. In the bottom picture, by shutting off the CMYK
separations, you can verify that the white has been properly set up for your project.