Press calibration

[Lukew]

We recently had our press calibrated using the TVI method , with just one coated profile created to be used for coated/uncoated.
We have now had an additional profile added, one specifically for uncoated, now what concerns me is when the company created the coated profile we ran the press with coated stock to get the dot gain % right, but can you please tell me how a properly calibrated uncoated profile can be created without running plates or press sheets?? is it just simply a set figure below what a coated profile is used across the board? I would have thought every press would print with different dot gain percentages simply from say different blankets/ink/fount solutions
Also why is it a waste of time calibrating by the G7 method if your using poly plates and your not printing complety high end work?
with the TVI method our m/c/y greys look anything but grey,lol

 

[rich apollo]

Re: Press calibration

> {quote:title=Lukew wrote:}{quote}
>…can you please tell me how a properly calibrated uncoated profile can be created without running plates or press sheets??

The short answer is, "It can't." Now, someone may have looked at average coated vs. uncoated dot gains for your set up based on old press sheets, or they may have simply pulled a number out of their...hat.


> {quote:title=Lukew wrote:}{quote}
> Also why is it a waste of time calibrating by the G7 method if your using poly plates and your not printing complety high end work?

It wouldn't be. I've done G7 calibrations recently on heatset newsprint. You can go pretty far "out of the box". There are folks using G7 methodology for flexo, digital, newsprint, uncoated, multi-channel, et cetera, et cetera. The applicability of the standard profiles depends on your output conditions, but the calibration methodology is sound for pretty much any output.

 

[Lukew]

Re: Press calibration

Rich, Thankyou for confirming my suspisions.
No a densitometer didn't go anywhere near any prints on uncaoated stocks.
We were first told you won't even notice a difference running coated/uncoated profiles instead of just a coated profile accross all stocks..
When I asked how they could get a proper calibrated uncoated profile,without a test run to establish the baseline dot gain they simply said they knew what the figures would be....
Also my suspisions as to why they didn't want to G7 calibrate is not because of the print environment or the fact we use poly plates, but the simply fact the company that supplied the machine couldnt be bothered.(we are in a fully aircon factory that runs the same temp all the time)
I had spent countless ours reading up on G7 and printed out all the how to books aswell prior to asking for it to be calibrated that way, it just seemed odd that there beliefs went against. the majority of info that is available on the subject...

 

[disbellj]

I'm finding the same thing, and quite frankly it sucks when us prepress are telling our vendors something they don't know, and when they disagree, we can simply point to documentation on the subject. Sorry for yelling, not intentional, just that i wasn't going to start typing over again once i noticed it.

Regards,

don

 

[1Pressman]

Coated vs. Uncoated

Coated vs. Uncoated

With the Coated calculations done.
Uncoated is only "calculated" as a average varience.
All papers are differant!
I wouldn't be too picky, Unless you are having a hugh variance from proof to press sheet.(dull proofing paper).
Good luck!

> {quote:title=Lukew wrote:}{quote}
>�can you please tell me how a properly calibrated uncoated profile can be created without running plates or press sheets??

The short answer is, "It can't." Now, someone may have looked at average coated vs. uncoated dot gains for your set up based on old press sheets, or they may have simply pulled a number out of their...hat.


> {quote:title=Lukew wrote:}{quote}
> Also why is it a waste of time calibrating by the G7 method if your using poly plates and your not printing complety high end work?

It wouldn't be. I've done G7 calibrations recently on heatset newsprint. You can go pretty far "out of the box". There are folks using G7 methodology for flexo, digital, newsprint, uncoated, multi-channel, et cetera, et cetera. The applicability of the standard profiles depends on your output conditions, but the calibration methodology is sound for pretty much any output.

 

[prepresscolor]

As I sit at home, celebrating my UNEMPLOYMENT for almost a complete year I find it ammusing to see conversations like this. Everyone is "on the cheap" these days. Instead of hireing a person like me the companies are using their "best guess" to solve their clients problems. Of course you need to run press profiles! It almost goes without saying that different inks, paper substraits, and yes, even different pressmen run colors differently. Tell your managers to shop around a little they may just find some poor soul in your area, that has the knowledge and talent to give you what you really need, sitting at home by his phone, on his computer, desperately looking for the "next job".

 

[JosephG]

What programs are generally being used to create tone curves for press calibration in the CTP RIP? Programs I have found are: PressSign (Bodoni Systems), GMG PrintControl and Alwan Print Standardizer. Anyone out there using these or care to comment on these?