How Can Ink Mileage be Increased?
A recent newsletter from the Printing Industries Association of Southern California offered some sage advice for press operators. The amount of pigment in the ink has the greatest effect on ink mileage. Pigment is the most expensive ingredient in ink, which explains why less expensive inks usually have lower pigment content. The ink holdout of the paper will also have an effect on ink mileage. Paper coatings that keep more of the ink on the surface tend to require less ink.
Proper ink/water balance on press will reduce ink consumption. Any condition on the press that causes the press operator to run a heaver ink film will increase ink consumption. For example, any extra fountain solution on the plate will cause the ink to print lighter and the press operator will compensate by running more ink. Correct plate-to-blanket packing will also help ensure that a minimal ink film.
Software can also play a role. Over the past few years, several “ink optimizing” software programs have been introduced that separate images in a way that reduces the percentage of cyan, magenta, and yellow inks being used and replaces them with black ink. If this sounds like Gray Component Replacement (GCR), you are correct—in many cases the software is a proprietary flavor of GCR.
Other providers of ink optimization software claim to provide an entirely new way of separating images using new algorithms that enhance image quality and reduce the amount of process color ink. The savings vary by application, but some companies tout as much as a 30 percent ink savings.