RGB workflows and general color managing

[motormount]

I'd like to ask what traditional (not digital) offset printshops do with file preparation and color management.

Firstly if you accept native files - that's the ''easy'' part, if a printer has the infrastructure to work reliably with native files, then color manipulating/managing these files should be no problem to him, but then are you working in rgb mode letting the rip doing the separation or you work in cmyk inside the application giving the rip a cmyk tagged file?

Secondly, -and probably most commonly- in strictly pdf workflows if you color manage files,if you accept pdfx3-4 files etc.

(Here files are processed based on their cmyk percentages irrelevant of their profiles -if they have any-,and only time when color conversion takes place is when a job has to much ink for our old press to handle, where i use some ''ink save'' device link profile to drop down ink total.

If files contain non cmyk data,customer get's warned either sends files back or tell us to do the conversion ourselves and same as above then.)

Even though i read a lot about rgb workflows and late in rip separations scenario's, my real world experience doesn't provide me with lots examples of shops color managing their files - to be honest none, except from cases i read here.

I'm writing again that i'm mainly interest on offset printshops, not digital printers and if it is possible i'd like to hear some small description of the shop - if i get all answers from people in big shops-plants with 4-5 prepress operators and inhouse IT departments things should be very different from the average medium printshop with one man show prepress workers doing anything from customer service to postpress chores-.

Every answer is valuable,thank all in advance!

 

[rich apollo]

I ran Alwan CMYK Optimizer (now ColorHub), and reseparated every file that came in. When every file is properly separated for the substrate its printing on, things run much more smoothly. You can be much less restrictive in the files you accept, which makes things easier on your clients. Managing color in PDFs is MUCH easier than with native files - faster, too. Using something like Alwan, your black channel is protected, and after the files have been reseparated the color is more stable on press. For me, it worked out well.

 

[motormount]

Thanks for your info.

I've heard about Alwan, i can also reseparate files inside Prinect.

I rarely do because the policy is not to change customers cmyk numbers.My main question is this, that even though there are tools like the one you said, in most shops i know - like were i work - people are actually not color managing files.

They -we too- convert rgb's - haven't see any lab element in a pdf yet - with or without customer knowledge and approval and keep cmyk elements intact.

In Rip separations, must have read it countless times, closest see i've seen happening is letting a normalizer/preflight tool do the job, that's not in rip separation or i haven't understand what in rip separation is about.

One more thing:

Have you needed built your own custom profiles to separate files?

Thanks again!

 

[rich apollo]

I've used both custom profiles and standard/published profiles. Kind of depends on what's available. For example, you'll have a tough time finding published profiles for heatset newsprint. In the same place I used a white-point edited SWOP #5 Coated, and a FOGRA published profile for heatset super-calendared. If you've gone about calibrating your presswork to match a published standard, and your proofing is targeting that same standard, then you can certainly use the published profiles.

Most folks come from a background where it was frowned upon to "change" the customer files. There is a certain level of responsibility that you take on when re-separating files. On the other hand, a whole host of problems disappear. Proper workflow practices will minimize risks.

In-RIP separation is like the old PostScript days. Hit Command+P and print separations (I think). PDF is a composite file structure.

Now, what makes me uncomfortable is how most of the Front-End Workflows (Apogee, Prinergy, et cetera) go about ink optimization. The files are re-separated just before screening. I don't like this because proofing has all ready occurred. I would rather proof the re-separated files.

 

[gordo]

[SNIP]

Most folks come from a background where it was frowned upon to "change" the customer files. There is a certain level of responsibility that you take on when re-separating files. On the other hand, a whole host of problems disappear. Proper workflow practices will minimize risks.

I think the fear from the printer's point of view is that if the presswork fails to meet customer expectations then if the customer finds out that the job had been reseparated then that becomes the customer's out and they can place the liability on the printshop for any remakes. I'll wager that over 80% of newspapers reseparate incoming images and the customers are none the wiser. Most reseparation software gives the same final press result appearance as the original image would have - so the risk of issues is very low.

[SNIP]

Now, what makes me uncomfortable is how most of the Front-End Workflows (Apogee, Prinergy, et cetera) go about ink optimization. The files are re-separated just before screening. I don't like this because proofing has all ready occurred. I would rather proof the re-separated files.

What difference would that make? AFAIK, the inkjet proof does not use the actual source image data the way a halftone proofer would.

 

[motormount]

Prinect reseparates files - if you choose so- before screening so you can proof and feel safe, especially if you are not doing this in regular basis.

You are both right on why this is happening - not color managing files - but my main interest was to get if i could a picture of what others are doing.

I got only an answer here* -thanks again Apollo- and two others in b4print.

As Laurens from prepressure said interest in prepress is waning, or maybe i'm not doing the right questions...

I'd expect big houses to do color management due to their financial and human recourses and the ROI a well organized color workflow should offer, medium ones to do or not depending on the insight of management and people in charge of the prepress departments and small ones mainly not to.

Maybe others could share their experience too, especially people who offer their services in various shops!

Thanks again!

*not counting Gordo's which was more explaining practices, not less helpful though!

 

[rich apollo]

What difference would that make? AFAIK, the inkjet proof does not use the actual source image data the way a halftone proofer would.

I guess that's where I refuse to let go of the past. I don't proof before trapping, I don't change the file after proofing. Hard lessons from the Postscript Wars.