Many people want white inkjet ink. Sign makers need white ink to print on dark materials. Print shops need white ink as background for translucent materials for images in colour. The textile industry needs white ink so they can print onto dark fabrics. For UV, solvent and eco-solvent situations, white ink can be a spot colour for printing on transparent material. This article by Dr. Nicholas Hellmuth from FLAAR Reports appears in Sign Africa Journal.
Artists also frequently ask why they can’t get white ink and photographers would like to experiment with the effects white could add to the mood of their fine art prints. But why is it so hard to make white ink actually function in real life?
Titanium dioxide is not easy to keep properly mixed. So your printer needs effective technology to keep the pigments in suspension. A cheap printer might have a cheap method while a high-end printer would tend to have a more sophisticated solution. Be a bit careful when manufacturers are claiming their white ink works: because when I visit print shops that have this ink, they are less than satisfied. White UV ink may be grainier than other colours because more is laid down to make it opaque, and because the drop size may be larger.
Where Does The Manufacturer (Engineer/Designer) Put The White Ink?
Every printer manufacturer handles white ink a bit differently. Be wary of cheap UV-cured printers that offer white ink with only one printhead. These companies offer white ink only to lure you into considering their cheap printer over a more expensive white ink system that actually functions for more than a week or so. You probably need at least two printheads to handle the white ink, otherwise it is not opaque enough.
If the white ink is in a mid-range model, it will offer at least two printheads for white ink, so there is enough opacity. White ink in a more sophisticated printer will offer several printheads up front and several printheads at the back of the row. This way the printer can jet white ink coming or going.
Software And Hardware To Handle White Ink
Merely adding another ink line, and putting in white ink, is not enough. The hardware has to have a method to keep the pigment in suspension without clogging the printheads or settling out. The software (and hardware) needs to accommodate how the white ink will be applied: as a spot colour, before the rest of the colours, or printed at the end. Merely having white ink in the spec sheet is not enough. Many companies simply add a tank for white ink and feature white ink in their advertising. It is essential to learn which manufacturers understand white ink, not just the chemicals, but also the software needed to make the printer able to handle white ink. Even the position of which printheads handles the white ink is crucial.
But Do You, Or Your Clients, Really Need White Ink?
Inkjet printer manufacturers and distributors that do not yet have white ink go to great efforts to point out why white ink is a fad, and not meaningful. If your clients want white ink; if you would like to distinguish your capabilities from those of competitors who don’t yet have white ink, then white ink is something to consider. And, like many things in life, if it is available, go for it.
FLAAR Reports www.flaar-reports.org