30 different stocks, 4 B1 Presses (Really Old, Very old, Old, and fairly New)

[herbert]

Hi All

Ok... Let me paint a Picture

Material Types
Felt Board
Uncoated Board
Coated Matt Silk Paper
Textured Board
Carton Board white
Carton Board Yellow
Carton Board Backed
and many more...hopefully you get the picture

Presses

Heidelberg 102 x 3
XL105 x 1


Prinect Prepress and Printroom Manager for Prepress
Epson

Colour Monitored on Press by Image control Heidelberg on all presses


We proof to Fogra 39 deltaE of 2, this is measured on a regular basis for approval
We calibrate the presses to ISO Standard LAB and dotgains, based on Paper Type 1 (one common material coated and uncoated)

The Problem....

Due to the amount of stocks we use, the paper white and absorbency of the material, we get different results...

Questions

Do you have a calibration for each material (hopefully not) match to ISO for LAB and Dotgain and have a bespoke profile for each material?.....We print with UV Varnish and a yellow Board...UV make the print go yellow. mixed with the yellow paper...its miles out of ISO spec..

Do you just change the paper white on the ICC profile to match the material at proof stage and make a compromise at print stage ?

I find the ISO Spec so Black and white....if only we printed on Normal ISO Material !!!

Any Black and white advice would be welcome.....

Regards

Dan

 

[Bondi_dan]

Hi Dan,

Your post highlights the limitations of the ISO 12647-2 Standard.

12647-2 is effectively a 'process control' standard offering +/- tolerance values for the print manufacturing process using 'control variables' - i.e. Type 1 paper. The version of 12647-2 you are probably most familiar with describes 5 paper types - the 2012/13 revision now describes 8 paper types and introduces comments on grey balance within the +/- TVI tolerance. The comments in the new version of 12647-2 on grey balance do not equate to the Neutral Print Density Curves (G7) approach to ISO compliance. I don't like the new revision of 12647-2.

Parallel to the 12647-2 revision the USA has been working on a far sighted Standard which very practically answers your questions/needs. This proposed Standard is "ISO 15339 - Printing from digital data across multiple technologies" or as I prefer to term it: SCAMPS - Shared Colour Appearance across Multiple Processes and Substrates.

15339 is effectively a 'print product standard' as opposed to the 'process control centric' 12647-2.

A Print Buyer specifies a 'Standard Print Appearance' - selecting from a range of Reference Print Conditions (RPC) or if you like 'Virtual Printing Presses' published in the Standard.

From there the printer's responsibility is to reproduce the Print Appearance of the RPC on the specified process/substrate. Just like setting up for 12647-2 there is a bit of work at the start to get things right for 15339.

One of the key approaches which specifically addresses one of your questions is the use of SCCA - Substrate Corrected Colorimetric Aim: effectively calculating what the colour of your printed job will look like on a different substrate and knowing the new solid ink Lab* values. From there plate curves need adjusting using either TVI, Device Link or my preferred method G7 grey balance (Neutral Print Density Curve). SCCA can also be used to adjust a data set to be used in a proofing system to preview what will come of the press using the new substrate.

The 15339 approach on Type 1 paper produces a result 100% compliant with the goals of 12647-2 - "ISO legal" for want of a better (although clumsy) way to describe it.

To summarise, 15339 is a Standard which Print Buyers, who seek Brand Consistency in their Marketing Collateral specify a single RPC (Reference Print Condition) for a campaign that could include glossy brochures, flexible packaging on plastic, flexo on box board, corrugated boxes, uncoated direct mail campaign, business cards, etc. and all have a "shared colour appearance".

The same cmyk image printed on yellowy box board compared to a Fogra 39 proof and to a blue/white optically brightened paper will have a very strong Shared Visual Appearance - the match achievable with this method is extraordinary. In contrast following 12647-2's specifications for different paper types, Lab* target, TVI curves etc. all create a different looking printed job.

The new 2012 revision of ISO 12647-6 (Flexo) uses the Reference Print Condition (RPC) approach, a customer specifies the look of the job (RPC) and regardless of what ink or substrate is used the goal is always to match the appearance of the specified RPC.

The '15339' approach is being adopted as an ANSI (USA) Standard - it has had a bumpy path so far in the global ISO world for various reasons but more steps will be taken soon.

My most recent personal update on this thinking and approach was in January when I went to New York for a course conducted by RIT to be trained as a PSA (Printing Standards Audit) Consultant. The USA approach is to recognise not every job is printed on Type 1 paper and we need a method to control and measure the appearance of print using different inks and substrates.

Away in the future I think it will be common for the 'print appearance' to be defined by the (global) print buyer and print manufacturers will use whatever tools they have to meet the goal of a Shared Colour Appearance.

I am based in Dublin, Ireland but travel anywhere for work


Dan Wilson

PSA (Print Standards Audit) Consultant
G7 PCC (Process Control & Conformance) Expert
UGRA Expert Consultant (PSO TVI Method)
FIRST - Flexo Colour Implementation Specialist
Chair - Ireland TC130

 

[Deleted member 16349]

Away in the future I think it will be common for the 'print appearance' to be defined by the (global) print buyer and print manufacturers will use whatever tools they have to meet the goal of a Shared Colour Appearance.

This finally looks like a good direction. I hope they do it right.

I suspect they won't get it right fully at first since I think to do this right and in a practical way probably requires measuring technology that is not yet available to make things simple to obtain large LUTs.

 

[herbert]

Hi Dan

Thanks for the indepth reply and thankyou for the effort, Much appreciated.

Its so difficult to try and not get caught up in the ISO Standard. and your reply confirm that, yes, we can print to ISO12647-2, on the correct material, and get accredited, but thats not our business (10%)..Is it a case of not letting the ISO Standard rule what we do, if it doesnt fit

These are our plans...

1 - Get Accreditation for ISO 12647-2, this will make the senior Management Happy...I understand how we need to do this.

2 - Collate all common Material, measure Paper white and create bands ie.
Band A - ISO Lab compliant
Band B - Coated Carton / Greeting Card White - Non ISO Lab compliant
Band C - Coated Carton / Greeting Card Yellow
Band C - Coated Plastic
Band D - Uncoated - ISO complaint
Band E - Uncoated - Non ISO Lab compliant
Band F - Felt and Textured Board

3 - For all Bands create bespoke Calibration and Proofing Profiles

Dan, I would really like to know about ISO 15339....

Can anyone tell me the best way to measure Paper white and does anyone disagree ?


Regards

Dan Marshall

 

[rich apollo]

I think you're on the right path. 12647 is only applicable to a specific set of printing conditions. In your case you're gonna' be doing a lot of press testing and profiling. I would also look very seriously into a color server.

To measure the paper white you'll need a spectrophotometer. If you have any X-Rite 500 series or better, they will work, too.

 

[rich apollo]

I think you're on the right path. 12647 is only applicable to a specific set of printing conditions. In your case you're gonna' be doing a lot of press testing and profiling. I would also look very seriously into a color server.

To measure the paper white you'll need a spectrophotometer. If you have any X-Rite 500 series or better, they will work, too.

 

[Potonka]

Agree with Rich. Probably going to have to profile each substrate. IDEAlliance has a calculator you can use your substrate Lab readings to create new patches for characterization chart you can then use for the ICC. We have 40 different materials, but they have a close enough white point, I don't use it. But thought I'd share anyways.

Substrate Relativity Calculator Kit 20120606 | IDEAlliance

 

[D.M.]

Similar to herbert, we have several dozen of different paperboards. I have tried Substrate Relativity Calculator for preparing ICC profiles. Also I have tried do the same in ProfileMaker 5. After changing white point in PM5 I have received different results than with IDEAlliance calculator. I compared it with printed sample. Better results with PM5.
Could You explain me what is the difference between changing data (white point) with PM5 and with SR calculator?

 

[Potonka]

When using the SRC, it adjusts the patches to the Lab values for the ICC chart. When you adjust white point in PM5, it is after the chart has been scanned and I assume the ICC is adjusting to your custom white point.