WHAT IS WHITE INK?
White Ink is simply the ability to print the colour white. Having this ability allows designers to expand the possibilities when digitally printing on coloured card stock and metallised papers. Most digital presses print a standard CMYK colour gamut (Cyan, Magenta, Yellow and Black). Some higher end digital presses have additional capabilities to allow for white ink, clear coatings, pantone colours and metallic ink.
HOW TO USE WHITE INK?
When creating digital design documents intended to use CMYK and white ink the designer needs to create an additional spot colour layer named "white ink." Ensure this layer is always set to overprint. This ensures that the white colour prints underneath the CMYK image. For example, pastels printed on a dark paper will require a base or undercoat of white ink to ensure the pale colours are soft. If the white ink layer is not set to overprint, then the white ink will simply be digitally knocked out and will not print leaving the CMYK colours muddled by the card stock colour.
Just like one coat of white paint on your wall is not sufficient to turn that feature wall in your house back to pure white, white ink printing often takes multiple “hits” or “passes”. In general the darker and more fibrous the card stock, the more hits are required… and each pass or hit adds to the cost of the printing. It is possible to create a complex wispy cloud like effect with white ink by applying several different hits of artwork and opacities.
WHEN TO USE WHITE INK?
If you are looking to use specialty coloured card with CMYK graphics, white ink lettering creates a distinguished reversed look. A designer can take the design on coloured stock to the next level by, for example using white ink as a base layer and printing pastel or vibrant colours on a dark board. Finally, unique foildboard, holographic stock and neon board stock can produce high impact results far beyond the CMYK gamut when used in conjunction with intelligent use of white ink and CMYK opacity. White ink is a cost effective technique for both short and medium runs.
ALTERNATIVES TO WHITE INK?
Alternatives to white ink printing are both digital and traditional “white” foiling. This embellishment technique uses a “die” and the white is “stamped” onto the paper using the heated foil die and pressure. With this technique, the white colour is strong with one pass, but will typically need to remain visible. This process is appropriate when white text is required, but falls short if CMYK pastels colours are required as an overprint on a white base. Variable data text can be achieved using digital foiling where ink or toner is first printed on the dark card and then the foil is transferred to the “printed” area. Again this works when white is in isolation but breaks down if complex multicolour or CMYK printing is also required.