Snowflakes

gordo

Well-known member
644 Snowflakes.jpg
 

SteveSuffRIT

Well-known member
When visually evaluating two images (proof vs press), distance and proximity is important!
The closer together the "this vs. that" are (butt, juxtaposed), the more sensitive we are to seeing differences.
That why press operators fold, tear, cut press samples and lay them next to the reference, target, aim, standard.
We DON'T want the customer to use this same technique.
We suggest customers do comparison viewing from outstretched arm length.
We don't use a magnifier (loupe) to look at color!
The loupe is only for register and print defect investigation (dot doubling).
 

gordo

Well-known member
I think the cartoon is referring to variation in the result more than variation from proof.
Gordo?
Correctomundo. :)
On a sidebar: when the presswork doesn't align with the proof the typical explanation is that "we beat the proof" or "looks much better than the proof" ;-)
 
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SteveSuffRIT

Well-known member
The objective is to closely match the "contract" proof (target, aim), within practical reason (tolerance limits, 95th % CRF cumulative relative frequency curve).
Ever read the fine print in gray ink on the back of the quote, it's called the printing trade customs and the printer decides what it normal or not, "commercially acceptable!"
It's common to try to "sell" the mismatch of the printing by saying we printed "better" than the proof. It looks sharper, brighter, better.

Getting back to the original post, Variation always exists, almost nothing is identically, exactly the same, perfect!
It depends on the measuring tool's precision or resolution. I always round to nearest tenth decimal for Lab, LCh, dE.
Are you looking at it under a 10x loupe, or from normal viewing distance, ~18".
To describe the variation or precision, calculate the standard deviation or sigma.
Compare it target aim for accuracy and specification tolerance limits for in/out of spec and are/are not capable (statistical measures of Cp, Cpk).
Sorry to get technical, I enjoy Gordo's comic humor.
 

gordo

Well-known member
The objective is to closely match the "contract" proof (target, aim), within practical reason (tolerance limits, 95th % CRF cumulative relative frequency curve).
Ever read the fine print in gray ink on the back of the quote, it's called the printing trade customs and the printer decides what it normal or not, "commercially acceptable!"
It's common to try to "sell" the mismatch of the printing by saying we printed "better" than the proof. It looks sharper, brighter, better.

Getting back to the original post, Variation always exists, almost nothing is identically, exactly the same, perfect!
It depends on the measuring tool's precision or resolution. I always round to nearest tenth decimal for Lab, LCh, dE.
Are you looking at it under a 10x loupe, or from normal viewing distance, ~18".
To describe the variation or precision, calculate the standard deviation or sigma.
Compare it target aim for accuracy and specification tolerance limits for in/out of spec and are/are not capable (statistical measures of Cp, Cpk).
Sorry to get technical, I enjoy Gordo's comic humor.

"I may not know about Lab or Lch dE but I know who pays the bill."
Buyer.jpg


Thanks for the kind words about my toons - it's appreciated.
 

chriscozi

Well-known member
The objective is to closely match the "contract" proof (target, aim), within practical reason (tolerance limits, 95th % CRF cumulative relative frequency curve).
Ever read the fine print in gray ink on the back of the quote, it's called the printing trade customs and the printer decides what it normal or not, "commercially acceptable!"
It's common to try to "sell" the mismatch of the printing by saying we printed "better" than the proof. It looks sharper, brighter, better.

Getting back to the original post, Variation always exists, almost nothing is identically, exactly the same, perfect!
It depends on the measuring tool's precision or resolution. I always round to nearest tenth decimal for Lab, LCh, dE.
Are you looking at it under a 10x loupe, or from normal viewing distance, ~18".
To describe the variation or precision, calculate the standard deviation or sigma.
Compare it target aim for accuracy and specification tolerance limits for in/out of spec and are/are not capable (statistical measures of Cp, Cpk).
Sorry to get technical, I enjoy Gordo's comic humor.
Can I quote your techno-babble the next time my client complains?
They'll probably go glassy eyed and I'll win the argument.
:)
 

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