The weakness in this story is they were assuming 50,40,40 cmy = 50% k.
Calibrating, Printing, & Proofing by the G7 Method for Flexography
In fact 50,40,40 cmy = 53% k.
It was written back in 2009, there is a new version of ISO 12647-6 coming out this month (I believe) and it specifies different Lab* co-ordinates to the ones referenced in the story.
Doing G7 on Flexo is as straight forward as Litho (or screen printing) if you document and control the variables.
Thank you for the link to the article Dan, it should be of great help to the OP.
Originally Posted by Bondi_dan
If the 50/40/40 was printing neutral then I would not be too concerned that it was 3% higher than 50% black.
Moving away from flexo for a second, the 50c40my value is often used as a neutral midtone aimpoint in say ISO Coated/F39 offset conditions on type 1 paper. If one is printing in these conditions and wishes the neutral midtone grey balance control to be closer to 50k, then one would likely get better results using 45c36my.
Last edited by Stephen Marsh; 12-14-2012 at 05:42 PM.
The original link was posted by Lammy much earlier in the discussion, he was able to name the link: "Calibrating, Printing, & Proofing by the G7 Method for Flexography" but I could only copy the browser address in my response.
Originally Posted by Stephen Marsh
I would not actually recommend following the process outlined in the story - it was a report on a research project and I think if they had contacted the good people at the FTA (Welcome to Flexographic Technical Association) or talked with a FTA FIRST 4.0 Implementation Specialist (like myself) they would have taken a simpler approach and got a quicker and better result. They would have been gently prodded into looking for the correct target values too :-))
The best approach would be to get a copy of FIRST 4.0 from the FTA.