The assumption that paper is white is, of course, faulty. So-called white papers come in varying shades of white and degrees of brightness. Then there are coloured papers and transparent media, such as self-adhesive vinyl. Producing “white” is a real problem for inkjet printers.
That’s why I’ve always wondered why inkjet printers don’t include a white ink. Even my HP Z3100 with 12 inks doesn’t have white. A white ink makes so much sense to me. It would extend the gamut, provide more accurate colour profiling and open up more creative options.
Adobe InDesign understands there is a difference between “White” and “Paper”. Too bad my printer doesn’t. Apart from the extra cost (which I don’t think would deter me), is there a good reason for this?
I would like to clarify, white ink is available. It is available on large format inkjet printers. It did take a few years to develop a working solution, but their is a solution. When it comes to smaller format machines, there are a few issues with white ink that need to be addressed. Pigment load, pigment fallout, and nozzle blocking. First pigment load. In order to get a “good” white ink the ink needs to have a sufficient load of pigment to produce an “opaque” white. Next comes pigment fallout. One you achieve a sufficient quantity of pigment load, the ink needs to be inconstant motion to keep the pigment from settling out of the ink. So when the ink is in it’s storage container is needs to be constantly agitated/moving. Lastly is nozzle blockage. Let’s just say that we solve the movement of the ink in the cartridge/storage tank. We also need to keep the ink moving in the head. If not the pigment will settle inside the print head and block the nozzles. When working with smaller format printers, you can see the difficulties to be overcome. Some of the large format printer manufacturers have solved these issues. I can speak from experience, the Inca large format printers with white ink produce an excellent white ink, and do not have the issues listed above.
Thanks for the info John. I guess my 44″ printer isn’t “large format” enough! 🙂
Brad