RGB or CMYK?

[ekuna]

Should it matter to the retouching house if I work in
RGB or CMYK? You can always convert the mode - is it
such a big deal?

[andrewrodney]

Yup, its a big deal! Conversions are not lossless, in terms of the data and color gamut. There are not CMYK capture devices, everything starts out in RGB of some flavor. CMYK is an output color space, intended for a specific print condition and thus, should be done as one of the last steps.

[madclark]

I concur. CMYK being a subtractive color model is less optimal for evaluating and prepping files on-screen. RGB and CMYK have different color spaces and CMYK gamut is smaller than RGB generally anyway. AND RGB files apparently take up less space than CMYK. You should save converting to CMYK as a last step in pre-flight if you're specifically optimizing to that for printing.

[ekuna]

Well, the thing is they want me to work in CMYK from start to finish,
no RGB! What's the point?

[madclark]

Who is "they" and why would they want you to work in CMYK from start to finish if they didn't know any better? Maybe you should describe exactly what the project is because either "they" don't know what they're doing or they need it this way for a specific reason that we could better explain if we knew what that was. Are the images coming to you in CMYK to begin with perhaps? Are they specifying CMYK to optimize the image for print (because there are better ways of doing that when you do the final conversion to CMYK at the end)?

If this was a reputable retouching house, I can 't imagine any reason why they would want you to work in CMYK if it were normal circumstances.

[ekuna]

This is a big and pretty reputable prepress company with a huge retouching
department. Images are coming in RGB. Of course conversion is done to optimize
images for print, but not at the end - first step before retouching is to convert RGB
image to CMYK. I'm trying to find the reason, if there is any.

[SilvaFox]

Could be the photographer or art director has told the pre-press company that the images coming in for this project are being done by an outside retoucher and will require no conversions, adjustments or corrections for press.

If that's the case, the pre-press dept. would want you to work in CMYK so they are not responsible for what goes to press. Many newer art directors and designers have a hard time with what happens to RGB during conversion to CMYK.

Nobody wants to be the one to explain why a beautiful RGB file turned to mud on press. At least with CMYK, you are reasonably sure what numbers will produce what color on press.

But that's just a guess. Maybe "they"re idiots.

[andrewrodney]

Originally Posted by ekuna

Well, the thing is they want me to work in CMYK from start to finish,
no RGB! What's the point?

Then if it output’s like crap, you better have an out. If they expect you to do any tone or color work, you better have an out. You can’t be responsible for how the image reproduces when you are handed CMYK and expected to alter the tone or color, its in an output color space, ready for print.

Worse, if after retouching, they want to repurpose the data (print it to another type of device), they are SOL.

[Heretic]

i work for a place in Toronto (one of the largest photo studios/ prepress shops in Canada) that retouches mostly in CMYK, only a few of us truly understand what RGB has to offer and refuse to do anything but the final step in CMYK, we tried to show everybody the benefits and logic of working in an RGB color space but they think we are just trying to pull the wool over everyones eyes.

sometimes it is just the lack of understanding and ignorance that leads a company, or hiring friends and relatives not Prepress people.

[pixelzombie]

Originally Posted by ekuna

This is a big and pretty reputable prepress company with a huge retouching
department. Images are coming in RGB. Of course conversion is done to optimize
images for print, but not at the end - first step before retouching is to convert RGB
image to CMYK. I'm trying to find the reason, if there is any.

that is the norm these days for most prepress companies, especially when they know the bulk of their work is going to a 4/c press..another reason is due to the fact that most prepress retouchers have much more experience with CMYK color...

[andrewrodney]

Originally Posted by pixelzombie

... they know the bulk of their work is going to a 4/c press..

Which 4 color press, running which paper? They are all different. Burning in retouch work in a highly device dependent color space is mightily inflexible. Now maybe this shop does this so that should another output be needed, they start from scratch (including retouching, proofs, etc). Its a great way to keep the profit margins up. But scan once, use many, an RGB approach is far more flexible. You can convert to any CMYK or other color model as often as you wish after all the retouch work. Putting the cart before the horse in terms of conversions is great when you charge by the hour and love doing the same work over and over again but its a prehistoric workflow by today’s standards.

[SilvaFox]

Originally Posted by andrewrodney

Putting the cart before the horse in terms of conversions is great when you charge by the hour and love doing the same work over and over again but its a prehistoric workflow by today’s standards.

I'm sorry. What does this mean? Correcting color in CMYK from a CMYK marked proof (inkjet) is prehistoric?

[andrewrodney]

Originally Posted by SilvaFox

I'm sorry. What does this mean? Correcting color in CMYK from a CMYK marked proof (inkjet) is prehistoric?

Nope, correcting color based on one output device when multiple output needs may be required are prehistoric in terms of workflow. Or to put it another way, you fix the image for output A and all you output is to device A, fine. You try to send that to any other device, you’re in a world of hurt. Do the same in RGB, then convert to as many output devices as you wish to use. No pain here.

[pixelzombie]

Originally Posted by andrewrodney

Which 4 color press, running which paper? They are all different. Burning in retouch work in a highly device dependent color space is mightily inflexible. Now maybe this shop does this so that should another output be needed, they start from scratch (including retouching, proofs, etc). Its a great way to keep the profit margins up. But scan once, use many, an RGB approach is far more flexible. You can convert to any CMYK or other color model as often as you wish after all the retouch work. Putting the cart before the horse in terms of conversions is great when you charge by the hour and love doing the same work over and over again but its a prehistoric workflow by today’s standards.

it is prehistoric but it does work, the images get converted to their working space and the output profile takes care of the rest, i'm curious to hear what workflow you prefer...

[andrewrodney]

Originally Posted by pixelzombie

it is prehistoric but it does work, the images get converted to their working space and the output profile takes care of the rest, i'm curious to hear what workflow you prefer...

What do you mean they get converted to their working space? They are in CMYK, that’s an output specific space (highly device dependent).

Don’t tell me someone is now going CMYK output to RGB working space? What’s worse than prehistoric?

[pixelzombie]

i was referring to a CMYK working space...

[andrewrodney]

Originally Posted by pixelzombie

i was referring to a CMYK working space...

A CMYK color space (working space if you will) is an output color space. A true, RGB working space (editing spaces) are output agnostic. They are archive color spaces. We edit in them, then convert to an output space as the need arises. One of the very last steps for a flexible color management workflow is the conversion to the output space such that all edits can be utilized as often as necessary without having an output condition forced upon them. If you edit in an RGB working space, you can convert as the last step as often as desired, the edits are not locked into an output color space condition.

RGB working space are also smaller in size, have a higher gamut and are often a higher bit depth. The only reason to retouch on a CMYK, output dependent color space is if someone forces this workflow onto you.

[SilvaFox]

That was the OP's point. This sounds like a specific CMYK environment. That's what prePRESS is. What looks pretty in RGB has very little in common with dot percentages and ink on paper.

The only thing anyone needs from him is CMYK. "They" don't want RGB because they don't want to fix, (or pay him to fix) what is going to be out of gamut every time they convert to CMYK.

Besides, the OP could work in whatever mode he wants, as long as he submits (hopefully press ready) CMYK.

Cheers

[andrewrodney]

Originally Posted by SilvaFox

That was the OP's point. This sounds like a specific CMYK environment. That's what prePRESS is.

The OP didn’t have a point, the OP had a question (Should it matter to the retouching house if I work in RGB or CMYK? You can always convert the mode - is it such a big deal?)

The answer is yes, it matters, its a big deal. The answer is, if the data is provided in CMYK and the output isn’t highly defined and fixed, AND if the OP alters color and tone, its very possible the OP will end up in a world of hurt when the press sheets come off the press with color and tone surprises! It has nothing to do with what looks pretty in RGB. RGB can become any CMYK variant at which time, it probably will not look “as pretty” but will reproduce as expected IF handled correctly. CMYK is a fixed color space for a very, very specific output. You can’t put that toothpaste back into the tube.

IF someone in prepress hands you output ready CMYK, sends the numbers to that specific device, you can retouch till the cows come home and everything should be fine. If however the numbers are intended for more than one device, all bets are off. You’ve burned the retouch work into a document that is solely intended for one print condition, period. That’s a highly inflexible workflow but great if you are charging customers for multiple retouch, press work (or you know for sure, the print job will only go to one device forever).

The only thing anyone needs from him is CMYK. "They" don't want RGB because they don't want to fix, (or pay him to fix) what is going to be out of gamut every time they convert to CMYK.

That was specified by the OP where? The OP said “Images are coming in RGB. Of course conversion is done to optimize images for print, but not at the end - first step before retouching is to convert RGB image to CMYK. I'm trying to find the reason, if there is any.“

As for out of gamut, that’s exactly why work that is to be repurposed should be in RGB because every CMYK space has a differing gamut that can be optimized during the conversion.

Besides, the OP could work in whatever mode he wants, as long as he submits (hopefully press ready) CMYK.

The key word here is hopefully. The part that is totally vague in the above is “press ready”. Press ready for what type of press, ink, paper, press conditions etc? They are all vastly different.

In the end, the OP has to provide what the customer wants but that doesn’t mean the OP shouldn’t understand the ramifications of an inflexible CMYK workflow. Again, if the prepress house wants to lock the retouch work into a one time usable file, that’s fine. It doesn’t make it a modern nor flexible workflow and now the OP knows why.

[SilvaFox]

Was there a problem with me saying "Cheers" at the end? You didn't comment.

[andrewrodney]

Originally Posted by SilvaFox

Was there a problem with me saying "Cheers" at the end? You didn't comment.

Wasn't my favorite show, I prefer Fraser.

[SilvaFox]

Just as I thought.

[Heretic]

this is an argument i have fought over in my place for years, some people just don't understand RGB to CMYK conversions and how device specific they are, and how destructive a CMYK profile can be to an output device if the profile is a mismatch. you will never win this battle.

[ekuna]

The reason apparently is much less intricate than I thought - it's all about who's on top.
And on top is the retoucher who is not very familiar with RGB, so he simply refuses to deal with it at any step of retouching process!..
Oh, and did I mention I hate working in CMYK?