Unhappy Returns

gordo

Well-known member
608 Unhappy Returns.jpg
 

Ulrich

Well-known member
Our experts had done a second proof by ourselfes that matches the print much more than yours, will you not agree the fault is on your side, if your proof does not match the print?
 

chriscozi

Well-known member
I must be misunderstanding the point to the cartoon and the comments.
If I view the proof and the product at the same time under the same light, they should match. Correct?
Or is the printer claiming that when they view the product and the proof under their ISO lights they DO match and that's the only way to tell they match?
And 'We don't do returns."?
Good luck with that.
 

gordo

Well-known member
If I view the proof and the product at the same time under the same light, they should match. Correct?
No. Proofs and presswork typically use different pigments/dyes as colorants. Because of that the spectral compositions will be different which in turn means that they can respond differently to the spectral composition of the light used to compare them.
Proofs and presswork are referred to as a metameric pair because the colorants match under at least one combination of illuminant and observer. But because of their different spectral composition they may not match under different lighting conditions.
Or is the printer claiming that when they view the product and the proof under their ISO lights they DO match and that's the only way to tell they match?
And 'We don't do returns."?
Good luck with that.

Most retailers/suppliers have a return policy. What about printers?
 

chriscozi

Well-known member
Proofs and presswork are referred to as a metameric pair because the colorants match under at least one combination of illuminant and observer. But because of their different spectral composition they may not match under different lighting conditions.
I understand this part.
So when our proof and press sheet match under our strict lighting conditions and match at least as closely in 'outdoor sunlight' why can't a customer take their sample and proof outside to compare?
 

Ulrich

Well-known member
cloudy sky?

If I view the proof and the product at the same time under the same light, they should match. Correct?
Using a customers proof he ordered by an Internet-shop made for offset coated paper but with ISO_Coatedv2.icc (FOGRA39), but producing on Heaven 42 for example or printed according to coated paper all calibrated according FOGRA 51 with a paper that whitepoint is more than Delta E > 3 away from the whitepoint in the icc-profile PSOcoatedv3 (FOGRA 51) as stated on the printshop-site:
Good luck whith that! ;-)

I saw some(!) proofs with green passed measering bars on it and after a measering check done by myself half of the lights in the bar turned to red... ;-)
 

chriscozi

Well-known member
cloudy sky?


Using a customers proof he ordered by an Internet-shop made for offset coated paper but with ISO_Coatedv2.icc (FOGRA39), but producing on Heaven 42 for example or printed according to coated paper all calibrated according FOGRA 51 with a paper that whitepoint is more than Delta E > 3 away from the whitepoint in the icc-profile PSOcoatedv3 (FOGRA 51) as stated on the printshop-site:
Good luck whith that! ;-)

I saw some(!) proofs with green passed measering bars on it and after a measering check done by myself half of the lights in the bar turned to red... ;-)
And there it is.
If the printer doesn't have a correctly calibrated proof on the proper substrate failure is imminent.
We are heading towards a CMYK xerographic proof for a CMYK press on the job substrate.
I am interested in comments about that.
 

Ulrich

Well-known member
I had never worked with a tonerbased printing machine…:
But i remember told to me issues regarding varying heat affects the stability of color? (So that - the more constantly reliability of reproducing color in really small tolerances - is one of the main reason (with the smallest possible „stock“ of 1 sheet…) for inkjet in „proofing“, i would say…

tonerbased „inks“ (not sure in the terminology, sorry…) have more opacity than offset-inks, so next the influence of the whitepoint of the paper will have not such an effect as an offset-print, for sure not so much the more the color is nearer to the solids i would expect…

otherwise, if a xerografic-proofed measuring-bar simulating FOGRA39, 47, 51 or 52 passes a check with green lights it should work, but that will happen in lower tonevalues - where the paper is not compöetly „inked“ - only with substrates whitepoints smaller DeltaE 3 as in the used cmyk-profiles for the files and then i do not see a need for going that way ;-)

The problems using other papers i see also as the reliable constantability mentioned above is how to verify the xerografic proof (a softproof on screen, too by the way) whithout a special icc-profile for each substrate and the more the opacity egalizes the paperwhite-issue the less it is a prediction for an offset print…

seriously asked: did you earn the same solids on different substrates by Xerografy? Or just more nearer together as with offset?

but might be i am thinking to slow and limited…?
 
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gordo

Well-known member
And there it is.
If the printer doesn't have a correctly calibrated proof on the proper substrate failure is imminent.
We are heading towards a CMYK xerographic proof for a CMYK press on the job substrate.
I am interested in comments about that.
You can calibrate as much as you want but if the xerographic print does not form a metameric pair with your presswork under the proper ISO lighting conditions then you will be out of luck using the proof for contract color.
Test before you take that path so that you can set expectations appropriately.
 

chriscozi

Well-known member
You can calibrate as much as you want but if the xerographic print does not form a metameric pair with your presswork under the proper ISO lighting conditions then you will be out of luck using the proof for contract color.
Test before you take that path so that you can set expectations appropriately.
Absolutely. Thank you.
We have a G7 trainer/consultant working with us to establish ground rules and baselines.
 

chriscozi

Well-known member
I had never worked with a tonerbased printing machine…:
But i remember told to me issues regarding variying heat affects the stability of color? (So that - the more constantly reliability of reproducing color in really small tolerances - is one of the main reason (with the smallest possible „stock“ of 1 sheet…) for inkjet in „proofing“, i would say…

tonerbased „inks“ (not sure in the terminology, sorry…) have more opacity than offset-inks, so next the influence of the whitepoint of the paper will have not such an effect as an offset-print, for sure not so much the more the color is nearer to the solids i would expect…

otherwise, if a xerografic-proofed measuring-bar simulating FOGRA39, 47, 51 or 52 passes a check with green lights it should work, but that will happen in lower tonevalues - where the paper is not compöetly „inked“ - only with substrates whitepoints smaller DeltaE 3 as in the used cmyk-profiles for the files and then i do not see a need for going that way ;-)

The problems using other papers i see also as the reliable constantability mentioned above is how to varyfy the xerografic proof (a softproof on screen, too by the way) whithout a special icc-profile for each substrate and the more the opacity egalizes the paperwhite-issue the less it is a prediction for an offset print…

seriously asked: did you earn the same solids on different substrates by Xerografy? Or just more nearer together as with offset?

but might be i am thinking to slow and limited…?
Our iGen5 and Mitsubishi press are extremely consistent and well maintained.
The digital paper library has individual paper white settings that can be refreshed as needed.
The inkjet proof we use now has little to no consistency issues, I agree, but there are shortcomings involving gamut and dot size.
The transparency of the toner may be an issue that can't be resolved - but we are going to find out.
Thank you for the comments.
 

gordo

Well-known member
Absolutely. Thank you.
We have a G7 trainer/consultant working with us to establish ground rules and baselines.

Question…did the G7 consultant do an audit of the mechanical status of the press before doing any press calibration? If so could you describe what was done for the audit?
 

chriscozi

Well-known member
Our customers simply ask us to match their home inkjet printer. o_O
Don't remind me.
First, the proof didn't match their screen.
And they 'helpfully' provided a picture of the proof next to their screen.
Then the proof didn't match their inkjet.
And they 'helpfully' provided a copy from their inkjet.
After matching said inkjet they decided it 'didn't look the same.'
You can't make this stuff up.
Sigh.
Turns out the whole reason for the attempt was because the inkjet per print cost was thought to be too high.
Never placed an order, never saw them again, thankfully.
 
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chriscozi

Well-known member
Question…did the G7 consultant do an audit of the mechanical status of the press before doing any press calibration? If so could you describe what was done for the audit?
No audit. Just what we call a 'fingerprint.'
Conditions are optimized - roller condition and settings, blankets, etc. for all units.
Operators (not me) have performed this same process each year at minimum.
 

Bob_McC

Member
This reminds me of a customer (large retail catalogue & stores) who specified Deluxe Cool White for critical color viewing/matching. Their plan was that when the customer brought the goods to the customer service area in the store, they would compare the catalogue to the item under that same viewing condition and there would be a good visual match. While that sounded good, in reality it was not as good as using a daylight balanced D50 ISO compliant light source, so they converted all graphic viewing areas to follow the standard (ISO 3664:2009). Not to worry, this was about 35 years ago.
 

keith1

Well-known member
Years ago I was the operator on a single colour GTO. Had a customer from an ad agency. It was requested that I work with her to colour match ink for some pretty fancy stationery (many items). For just over 3 hours she had me pissing about. She'd take each new colour pull outdoors to view in sunlight.
After she left, my boss, who presumably had been hiding, asked what was going on. I explained and the ad agency was charged for the time.
All the stationery items were then printed on the 5 colour GTO. It was fancy, as only ad agencies can make it. Spot varnish, tri-tone & my special ink match.
The job came back the following week. Turns out the phone number was wrong. The fault of the woman who oversaw the ink match. Between the bill for the colour match press time and wrong phone number, she was fired.
 

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