Press can't match proofs after years of little trouble

[printguy27]

This is incredibly frustrating. Has anyone been through this? I feel like there's too many details to tell the whole story.

We keep searching for that X-factor that's making everything break down. One thing I keep seeing is that some jobs the ink on press seems weak, and we have to make a curve plate with a boost to a process color or 2.

Our only hope now is to successfully create a new press/proofer profile that's easier to match. We've tried to do it ourselves twice and have made ugly proof profiles both times.

We need to try again when it slows down here, but right now it's just job after job in the busy season going down on press and it's getting intense with emotions. Feels like somethings gonna snap.

 

[gordo]

Snipped for clarity.

Title. Press can't match proofs after years of little trouble.

One thing I keep seeing is that some jobs the ink on press seems weak, and we have to make a curve plate with a boost to a process color or 2.

Our only hope now is to successfully create a new press/proofer profile that's easier to match.

You seem to be saying that you used to be able to align your press work to the proof but now you can't?

Apparently something has changed in your process. Wouldn't it be better to figure out what changed and correct that rather than arbitrarily adjust plate curves?

Seeing is that some jobs the ink on press seems weak is somewhat meaningless. Have you measured solid patches of color - Ink density? Lab? Have you examined to halftone dots to look at things like over emulsification?

 

[prepressdork]

What Gordo said but to add to it, here are some questions to consider:

1. How long ago did you start having issues matching press color to proof?
2. Did something change right before this issue started? Such as...
   1. Ink vendor/manufacturer/recipe? Was something added to the inks to solve some other issue?
   2. Plate vendor/manufacturer/brand/type?
   3. Fountain solution brand/make? Dosage amount?
   4. If your fountain solution is a 2 step, did the alcohol sub change? Did the ratio of alcohol sub to fountain solution change?
   5. Has something about the press changed? Rollers? Blankets? Some other variable?
   6. Did you buy a new press?
   7. New batch of plates? Could be a bad batch.
   8. Proofer brand/ink?
3. Are the matching issues always/almost always with the same ink(s)? Maybe there is something wrong with the corresponding press unit or units?
4. Is the pressroom properly maintaining their presses (including rollers) and on a scheduled basis? Calcium build-up?
5. When a pressmen says he can't match color, do they bring you the plate(s) to look at? Do the plates show any anomalies like areas that are shinier than others? Areas that don't take ink as well as others?
6. Are your pressmen suddenly running their water too high? Too low?
7. If you have more than one press, have you tried printing a problem job on another press to see if the problem still occurs?
8. How old is your platesetter? Is it out of calibration? Perhaps the platesetter is in need of service? Maybe it's not burning the emulsion to the aluminum substrate well enough? Laser life is not infinite.
9. Plate processor? Is it operating within manufacturer plate specs in terms of temperature, speed, etc.?
10. Is the chemistry within the processor fresh? Does your processor need to be cleaned? Does your processor use water? If so, is it using city water? If so, maybe there is a contaminate?
11. Have you confirmed that all software settings in your rip are correct? Have you verified the linearization of your plates? That the correct plate curves are being applied?
12. Have you confirmed that all software settings in your color proofing software are correct?
13. Have you checked the calibration of your proofer? Does the proofer need re-profiled? Did you change proofer brands or buy a new proofer?
14. Are you using OEM or 3rd party inks in your proofer? If the latter, did you recently change to 3rd party inks?
15. Did you change spectrophotometer devices (or however you verify proof color)? Is said device calibrated correctly?

That's all I can think of at the moment.

Best regards,
pd

 

[Gianni_S]

I have something in mind about that, so I ask:
Are you using processless plates?If the answer is yes, have you noticed if troubles started when you adopted them?

Thanls.

 

[printguy27]

Some great responses here that are definitely things to consider. Sorry I haven't had time to reply in detail! Thank you folks

 

[SteveSuffRIT]

We seem to never have time to do it right the first time, every time, BUT we always find time (usually over-time) to rerun, remake for a customer rejection.
Short-term, temporary, band-aid "Fix" the problem or real scientific method trouble shooting and problem-solving for root cause analysis.
Pay me now, or pay me later?

 

[KimR]

print to the colourbars and measure. make your plates with a wedge to observe changes

 

[javeria]

If your press has suddenly stopped matching proofs after years of consistent output, here are a few areas to check:

1. Press Condition: Components like blankets, rollers, or dampening systems may have aged or worn out. Even minor mechanical changes can affect color stability.
2. Ink and Paper Changes: Has there been any recent change in ink formulation or paper stock? Even slight differences in ink tack or paper coating can alter color behavior.
3. Environmental Conditions: Seasonal humidity or temperature shifts in the pressroom can impact drying and ink laydown. Check if HVAC or dehumidification systems are consistent.
4. Proofing System Drift: It's possible your proofing system (RIP calibration, paper, or printer itself) has slowly drifted out of sync. Recalibrate both your monitor and proofer, and verify the RIP profile matches the press condition.
5. Color Management Profiles: ICC profiles might be outdated. Ensure you're using current press condition data when generating proofs.
6. Operator Habits: Subtle changes in press operator habits, such as ink key adjustments or washup procedures, can impact consistency.
7. Ink Density / Spectro Measurements: Remeasure your press sheets and compare Lab/DeltaE values to proofs using a spectrophotometer. Target G7 or FOGRA values depending on your standard.

Action Steps:

• Run a fingerprinting test to assess your current press condition.
• Recalibrate the proofing device and verify your RIP settings.
• Compare current DeltaE values against your original color targets.

 

[KimR]

I suggest with your limited time, get your pre-press right first. Too many variables will bog you down.

Run to the colourbars and measure. make your plates with a wedge to observe changes.

Within days you will see if its the plates or printer.