Discussion

By Cory Sawatzki on Mar 06, 2017

Great reporting as always, and wonderful work by Don, and Ron, and all those involved. In order to keep confusion down, should we not call it Extended Gamut instead of Expanded just by definition?

I have had several people reach out and ask me more about this process which is great. But you are really doing more with the same (Extended). Not adding more colors, or adding anything (Expanded).

Just food for thought....

By Eddy Hagen on Mar 06, 2017

Richard, this is indeed a (significant) improvement for offset lithography. But you forgot to (explicitely) mention two important aspects:
1) it works with standard cmyk inks (you did mention that density is boosted, but didn't explicitely mention that these are the standard cmyk inks)
2) it only works with FM and non-traditional screenings, not with AM screening (AM screening limits the gamut).
I think every offset printer should at least look into it, try it. It works on existing equipment, with current consumables. So changes in the printing process are rather limited.

By Ron Ellis on Mar 06, 2017

Photos above came from Don Hutcheson - he has many others that also show the differences as well.

By Gordon Pritchard on Mar 06, 2017

For clarity's sake - you can certainly print at higher than standard solid ink densities using standard AM screening - it's just that iDealliance chose not to go that route. This article from 2009 explains how: http://the-print-guide.blogspot.ca/2009/01/printing-at-dmaxx-maximizing-cmyk-gamut.html

I named it "Dmaxx" since that is what you're doing - printing at maximum solid ink density.

FM and higher than standard AM screening (300 lpi or higher) exhibit a larger gamut in single and two color screen tint builds compared to 175 lpi AM but not with 3 color builds (the third color has a neutralizing effect). Although the measured gamuts will be greater with FM screening, the value of that extra gamut is primarily in line art rather than raster images since raster images seldom have large enough single or two color flat tint areas to exhibit the effect visually.

When you increase solid ink densities you increase hue saturation - up to a certain point, however, in my experience, there is not much positive impact on gamut deficiencies (e.g. oranges and purple/blues) since the base ink hues remain the same..

On a technical sidebar - FM screening and very high lpi AM screening (300 lpi or higher) don't increase gamut. What they do is reduce the gamut less than standard lpi AM screening. The coarser the screen the more light reflects off of the bare substrate and is therefor is not filtered by the ink. This unfiltered light effectively greys the hue (reduces its saturation). High frequency screening allows for more light to be filtered by the ink rather than being reflected off of the bare substrate and therefore reduces the potential gamut less.