Expanded Gamut CMYK (XCMYK) is a four-color printing method, a dataset, and an ICC Profile.

Offset printing has made terrific strides in both quality and repeatability in the last number of years. Press-side instrumentation now enables us to read L* a* b* values for a more visual approach to colour rather than just ink densities which only give us an indication of ink film thickness.

GRACoL (General Requirements for Applications in Commercial Lithography), the sheetfed print specification for coated paper also gives offset printers numeric quality targets to aim for, and the G7 methodology from Idealliance allows printers to achieve this printing industry specification.

These best practices allow printers to reduce make-ready time on the press, lower paper waste, suffer from fewer re-runs and ultimately be more profitable than their competitors. Customers tend to be happier, sales people tend to sleep better. However, is running to the GRACoL sheetfed print specification really the best we can do?

In a very competitive industry, printers are always looking for an edge, and on December 1st, 2016, Idealliance, the non-profit organization that advances the offset printing specifications for North America formally announced the new Expanded Gamut CMYK (XCMYK) offset printing specification.

It’s not for the faint of heart, but certainly a welcome addition for art books and the like where the increased vibrancy of colour can make a noticeable difference. Here are some of the key elements to success:

1. Printing to the new XCMYK printing specification requires much higher ink densities. These higher densities are best achieved with highly pigmented inks, although good conventional inks have also been tested to work.
2. FM (stocastic, typically 20micron) screening was found to work best and also gave greater vibrancy to pastel colours.
3. It is best if XCMYK files for printing are produced from the original wide-gamut RGB images. CMYK to CMYK conversions should be avoided.
4. Most modern inkjet proofers and RIPs are capable of proofing to XCMYK using the new ICC reference profile.

As G7 Experts as certified by Idealliance, please don’t hesitate to call or write us for further information on the G7 methodology or a test proof to the new XCMYK print specification.