Ink densities always have to be increased to achieve good colour, match proof especially black solids when running overall matte AQ coating. The problem is dot gain goes from say 18% to 25% for C,M,Y and from 20 to 35% for black, so the screens look much darked than the proof while the solids look good. Does anyone know the best way to tackle this? Do all matte AQ coating have this characteristic of knocking back colour? Should I have a different plate curve for jobs with matte coating? The only problem is, I'll still be running a lot of ink on the rollers to achieve the colour with the matte. I'm open to any suggestions.
Most well run shops will have different plate curves and solid ink density targets for gloss coated, matte coated, and uncoated papers. A few will have different setups for AQ coatings as well. The idea is to create shop standards to optimize prepress in order to optimize presswork for different print conditions. They run tests and define their standards ahead of time so that they are not experimenting on live jobs.
We tried different curves, but not worth the effort. We found that the coating diffuses the solids and they read about 5-6 points lower (with coating). We have lower numbers for satin coat or don't coat the color bar and run to "normal" densities. If you run to normal densities with the coating, it causes more dot gain and the delta E of the ink changes not matching G7 tolerances.
Hello fellow Lithographers, learners and smudgers of ink on paper.
Fundamentals
Refractive Index and Its Importance, Scientists measure the reflecting qualities of different materials and give each a rating which is called the refractive index.
See the PDFs
"From knowledge to competence is a great step ----from ignorance to competence an even greater one"
Regards, Alois
****** You can Curve all you want !!!!!!
Last edited by Alois Senefelder; 03-09-2011 at 02:45 PM.
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Matte AQ coating kills colour
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