On May 29, 2014, at 8:42 AM, William Whitfield <billw@mlode.com> wrote:
Greetings,
FYI - I recently posted this to Print Planet. I am a flexo printer and have created a profile using iProfiler for a poly stock which has a very high TVI. In order to make an accurate proof I had to build what I would call, an extreme gradation in my CGS proofing workflow, which led me to believe the profile is not accurately reporting my highlight TVI.
I checked the TVI on press sheet with a 530; in ColorAnt using the measurement file; and, in ColorThink using the profile. ColorAnt matches the TVI in highlights that the press printed, but the profile in ColorThink does not. Here is the data for cyan:
Hi Bill! TVI reported from a profile is not the same as TVI using actual density values (which the 530 and calculations from the spectral values in measurement files will give you). I don’t want to get into an argument about which method is more or less valid (though I’m more likely to rely on density based myself) The simple fact is that we only have colorimetric information available in profiles and so we are left with using the XYZ method outlined on Lindbloom’s site. It has proven to be a fairly effective estimation and is becoming a popular method of calculating TVI but it can give different results. That said, perhaps the profile really is differing from where it should be. If you send it to me I’ll take a look. regards, Steve