Old School vs New School

[Red_Right_Arm]

I run a prepress department and have been getting a lot of backlash for inaccurate plates lately. It seems to me that there is a disconnect between three upper managers and myself as to what is the correct way to create accurate plates for press. The three upper managers come from 35 years of experience printing in flexo. They come from a time before computers, RIPs, or digital ∆E measurements. All they know of flexo printing is that you have absolutely no idea how a job will run until you get the plates on press and begin seeing what is coming out at the end. From there you evaluate the results and decide if you want to change your anilox, impression, ink density, or line screen on the plates. But until you start printing that live job everything is an unknown and it is the pressmen's job to monkey with the press until it starts to look correct. And so I will describe two scenarios below. I'd love to know A) If I'm wrong, and if so where do I go astray. B) If I am correct, how have people overcome this in other companies.

Scenario 1 (The throw everything at it and see what sticks approach)
- Digital proof is approved.
- A "color accurate proof" is printed. This proof runs through one set of color management that is the same for all substrates on all presses.
- The digital file is sent to the RIP.
- The RIP has one generic dot gain curve that is meant to be good enough for most substrates on most jobs.
- The plates are made using this curve.
- The plates go on press and begins producing labels to be evaluated.
- Based on the labels coming off the press, the pressman will change anilox rolls, ink densities, impression settings, and even different line screens on the plates.
- Once the various adjustments are made the pressman evaluates if they are making the labels look better or worse compared to the proof.
- After some combination works, the labels are measured to be within 2.0 ∆E of the proof or the Pantone book, depending on the colors.
- Prepress's job is to instinctively tweak the dot gain curve in order to anticipate the issues they are going to have on press.
- At times Prepress ought to know to make a variety of plates at a variety of line screens with a variety of dot gain curve adjustments so that the pressmen have options to try out as they are setting up the job.
- Color management can't possibly work for what we do because there is no way to know ahead of time which anilox, density, line screen, or impression will work to produce this job correctly.


Scenario 2 (The one I keep saying we should be using)
- Fingerprint all the presses on our most popular substrate, which should get us 80% of the way there.
- Create different generic profiles for each press based on these fingerprints.
- Decide which anilox to use first. Adjusting it is a last resort, not a first move.
- Keep consistent ink densities. Adjusting it in a controlled way is a last resort, not a first move.
- Decide which line screen to use on the plates first. Adjusting it is a last resort, not a first move.
- The pressman can play with the impression to see if it makes things better or worse, but that's about it.
- Allot time into the workflow for measurements and adjustments and a new set of plates.
- After taking measurements from the produced labels, the dot gain curve is duplicated and that's the one that gets tweaked for this specific job. The tweaks are based on the dot gain measurements coming off the press for this configuration.
- The adjusted plates are made and should run more accurately on press this time.
- If not, changing the anilox, ink density, or plate line screen still shouldn't be done.
- Measurements are taken, the plate is adjusted farther, and a new set of plates made.
- Repeat as many times as needed until new plates resolve the issue.
- If new plates aren't helping, then start messing with the anilox, densities, impression, or line screen.
- It means that every new job will need a new set of adjusted plates at first. But until we decide to do extensive fingerprinting for each variable on each press this is as good as it'll get.

 

[Puch]

Hi,

your workflow seems to be much better, but from my past experience, you can never persuade the owners to embrace it. Such company culture will only change when a.) the company starts failing (missed deadlines, quality concerns, clients leaving for other suppliers etc.), b.) a new, younger management appointed (eg. the owner's son/daughter get positions on the board). Until one of that happens, no force will change the way of thinking.

IMHO your only way to do something is to experiment in spare time, prove your concept, and present (very) hard facts: saved time, material, better quality labels, financial breakdown. Even after that you might be better off taking your hard-earned knowledge to another company which will respect your ambition an insight.

 

[Red_Right_Arm]

Puch,
I'm inclined to agree with you on finding another company. But I really want to break through and get this problem turned around, as challenging and frustrating as it is. The company is good. They just don't know any better. There has to be a way to get them to understand they need to change with the times. Thanks for your other suggestions about trying to produce hard fact data to show them.

 

[WI-Flexo]

Pretty good explanation from Gordos blog http://the-print-guide.blogspot.com/2012/02/who-is-responsible-for-print-shop-color.html

In basic terms:

It is management's responsibility (with input from prepress, press room, and sales) to establish what the presswork color targets and tolerances (dot gains, standards, specifications etc.) are for the presswork - because those are marketing/business decisions. Then provide the tools (training, resources, equipment) to allow prepress and pressroom to achieve those targets.

The responsibility of prepress is to align proofing to the target established by management as well as to maintain proofing within the tolerances established by management because tolerance targets are also marketing/business decisions. Prepress must also output plates that enable the press operators to align their presswork to the proofs with the press performing in a repeatable, stable, cost-effective condition.

The responsibility of the press operator is to manage the press in such a way that the films of the appropriate inks are laid down in a manner that meets the targets and tolerances (hue, trapping, etc.) established by management and that the halftone dots on the plate are reproduced with fidelity on the various substrates (avoiding slur, doubling, etc.). Also, the press operator needs to make sure that all press-related consumables (fountain solution, inks, etc.) are within the tolerances needed to achieve the management defined targets for pressroom output.


This is also the way we handle color at our shop.

Press creates a standard press setup (standard A)
Prepress fingerprints and profiles to that target (prepress matches press)
All proofs are then run to that original standard (standard A)
All press runs setup to that standard (standard A)
Deviations on press will create variance.
These deviation can be checked by comparing ink density to the fingerprint charts densities to check conformance.

Hopefully you will find as we did that running to the numbers makes everyones job easier and gives everyone the same expected results.

It is very rare that the pressroom will bring an items to prepress for color not matching and they will never bring us a run up that deviates from that original standard as that is the very first thing we will check.

Also keep in mind that in an ideal scenario the fingerprint will be done for all presses and material combinations. You may find some close enough to combine eventually but its good to make those decisions off actual numbers instead of guessing.

 

[davarino]

In the meantime, you may wish to read anything you can by W. Edwards Deming.

Deming is the American statistician who taught Toyota how to make cars dependably. His methods work in any industrial process.

There are several YouTube videos that cover some of his ideas: the Red bead experiment and the Funnel experiment are great introductions.

The essential idea in any pressroom is to set a mechanical standard that will reduce makeready to a minimum and avoid tweaking by designing ways to reduce variance. The time savings can be impressive.

I worked in flexo 45 years ago. Plates were always hand laid without any real reference markings. The first thing I did in our composing room was to introduce a bearer rule at the top and bottom of every form, with a rule to the side. Then the pressman scribed a line to lay the rubber plate... and afterwards he saved about 5 minutes on every makeready. (He had to trim off the bearer rules and the side rule once he had position, but he still saved that much time!)

Today's plates are different and faster to set up. But the concept of "keep the variables to a minimum" still applies.

There will always be variance: but the variance can be kept within limits if you're not adjusting every blamed knob there is and if you accept that you are working inside a fence of parameters.