Best results when changing RGB to CMYK

[_Aykut_Kaplan_]

Hi There,

How can I get the best results when converting a RGB to CMYK? For example, a tif visual when offset printing... Is there any programme, plug in, machine for this?

Many thanks

[LucienSchilling]

Photoshop - Illustrator - InDesign and respect your colour profiles (sRGB <> AdobeRGB etc).

Lucien.

[Guest]

To convert an RGB file to a target CMYK space, open the image file in Photoshop, then go to Edit > Convert to Profile.

Once there, select your target profile (a copy of which should be in the [Your Computer] > Library > ColorSync > Profiles folder, or else it will not appear in the pulldown menu).

Then select a rendering intent appropriate for your image (to simplify, Perceptual if the relevant image colors are out of the target's gamut, otherwise Relative Colorimetric). If you select Relative Colorimetric, it's also a good idea to check "Use Black Point Compensation".

Do NOT use the Image > Mode > CMYK command to convert your image, because that does not offer the degree of control that you have with Convert to Profile, and limits you instead to the target space and conversion controls set in the application's Color Settings, which may not be appropriate for your purposes.

There's more to all of this, of course, but that would be a good start.

[varsha321]

Thanks. That was really helpful !!!

[CarlBoudreau]

Thanks Marco for the "convert to profil" trick instead of juste "mode/cmyk". Didn't know that!

[gauravc2233]

Thank you @Marco your tip worked perfectly

[pullela_kartik]

Hello Macro,

I really need this question answered in a more simplified way.

I believe the solution/answer you provided was the right action to get the job done. But, I did not understand.

I am not a big expert of the color subject and not a technical expert. But I am in need for this.

I created a logo for a client in photoshop using RGB profile. Client approved the design and colors. And wanted me to provide the design in CMYK as well.

In the past, for the same purpose in photoshop, I used to open a new file with CMYK profile and drag the logo layers from RGB file to CMYK file. And publish the file into desired formats.

Was that a correct approach?

Pls let me understand the best way to do the needful. Thanks.

regards

Kartik

[Printrix]

If the colors chosen in RGB don't convert properly to CMYK they are probably out-of-gamut for your CMYK profile. Adobe RGB1998 has a gamut volume of 1,207,520 vs 402,102 for Fogra39 and 296,515 for US Web Coated v2. In other words 2/3rd of the colors available in Adobe RGB1998 are not (as in never) available in Fogra39 or US Web Coated v2. The best possible solution you can get is to convert using the "convert to profile" option in the Edit menu and play around with the rendering intents. I think you will get the best result with Relative Colorimetric with Black Point Compensation enabled. Another option (in my opinion the best) is to explain your customer that web colors (viewed on a monitor) are (and generally should be) more saturated than printed colors (business cards, documents, etc. printed on offset press). The average consumer eye adapts anyway to the color difference between the two. You rather have a saturated logo on a webpage and the closest match on print than a match between web and print as the logo on web would look very dull in the latter.

If you drag and drop a design from Photoshop to Illustrator the color will be converted to the color profile active in Illustrator (Menu -> Edit -> Colorsettings). I always prepare the designs with the same color settings in both Photoshop and Illustrator before drag&drop or place (Menu -> File -> Place).

Always to choose an adequate working space before creating your designs, it will prevent such issues. There are predefined settings depending on your region and application. You will have to switch very often between two of them, one for web and one for print. They're pretty self-explanatory:

North America Web/Internet or Europe Web/Internet 2

North America Prepress 2 or Europe Prepress 3

There a a few others like newsprint and general purpose but I never need/use them.

I advise to set the appropriate color settings before creating the new design.

Remarks:

- Whenever I convert between profiles I always play around with the rendering intents while the "preview" is enabled. This allows to quickly evaluate for the best conversion setting.

- Never include the sRGB profile for web applications in your files (option available after pressing "save as")! In Firefox you can enable colormanagement and logo's and pictures will look very dull on the screen of the user.

Regards,

Steven

[Maurer6455]

I'm replying to Stephen cause he sounds the most technical but I am desperate for help from ANYONE with this conversion.  I have created an Ad in PS15, Adobe RGB as I always have but this magazine is asking me for CMYK and 300+dpi. I followed Marco's instructions but didn't find "Convert to Profile" in Edit - anywhere, I clicked on every one of the drop-downs.  I DID find in Image "Convert Color Profile" with the only options to "Convert to sRGB" or "Convert to Adobe RGB" which I already thought I was in?!? I have to turned in on Friday (thank you Boss!) Help...please!

[Test Screen Name]

Suggest you post in the Photoshop forum. This forum is deserted and runs at a message every six months, while the Photoshop forum runs at a message every few minutes. That's assuming you have Photoshop Creative Cloud. If you have Photoshop Elements, this may be a product limitiation, it isn't really for prepress use, but try the Photoshop Elements forum.

[NB, colourmanagement]

HI Maurer6455





This is a particular forum that doesn’t get a lot of traffic, for sure.

For me, this is a colour management issue, rather than general photoshop, so I feel its ideal place would be the COLOR MANAGEMENT Forum here: https://forums.adobe.com/community/design_development/color_management - I’ll give you some answers here anyway.

Don’t start again lets do it here.

.

Also - for a new question it’s generally good to start a new thread title.

So, you made an ad. in Photoshop (you write "PS15"?) using the sRGB colourspace. Is that right?

Or you’re using Photoshop Elements?

The edit / convert to profile is definitely there in Photoshop!

Of course you’ll need advice on what CMYK profile to convert to. Each printing method has its own idiosyncrasies and paper type affects that too (coated/ uncoated etc). Also, printing in Europe uses different CMYK standards to the USA. You MUST ask the printer.

If all this seems a bit much, you’re right, for many it is too much responsibility - please do not make changes after guessing about CMYK profiles etc.

You would be FAR better to hand the sRGB file to the designer or printer and ask them to

1: make the conversion

and

2: make a proof so you can check appearance.

This proof [viewed in daylight, or ideally a proof viewing lightbox] should compare pretty well to the ad you made as viewed on your (properly calibrated) screen [viewed in a darkened room].

But some colours that can be created in sRGB cannot be printed, even on decent paper, and, as you move down the CMYK gamut [gamut = colour range] scale towards newspaper print it gets worse.

Don’t be downhearted, though, we’ve all seen ad’s for the exotic holidays, e.g. the Caribbean in newsprint and, although they colours are muted, they still can look good if the file was set up properly.

Photoshop has the tools for CMYK conversion, it offers various rendering intents to deal with colour repurposing during the conversion.

In this circumstance the logical choice would be between Relative Colorimentric & Perceptual Rendering.

The best way to learn about Relative Colorimentric versus Perceptual Rendering is to make the conversion those 2 different ways and check on your (calibrated) screen how satisfied you are with the result. Open the 2 converted files next to each other and compare and choose.

Photoshop also offers soft proofing which allows those working in RGB to preview the effect of the final CMTK conversion whilst they are working editing the file. Great tools.

Do you have Photoshop and you are working with Layers?

- then here’s a tip you may find useful:

Just FYI I suggest you flatten any layers (maybe make a copy of the RGB file first and archive the layered RGB if you feel the need, you may want to rework the file one day).

I hope this helps 


if so, please do mark my reply as "helpful" and if you're OK now, please mark it as "correct" below, so others who have similar issues can see the solution


thanks

neil barstow, colourmanagement

[Maurer6455]

Thank you so very much - my printers (I finally called them) said the same thing you did - basically, "If in doubt leave it as RGB and we'll test the colors before going to print."

[Golden373495893q3r]

Can you please tell how can we a convert a rgb design made in canva into cmyk(don't have canva pro) please suggest any free platform preferably any online  authentic site.

[_cliffinmi_]

I agree with Marco U.

I might have said: only use Perceptual if an extremely important color in a photo changes terribly using Relative Colorimetric -- otherwise use that. The reason: The former method can make the whole picture shift (usually yellower and weaker) but the latter can make several distinctly different colors (like 3-5 different reds for example) and make them the same. Usually, one or two really strong colors can get shifted somewhat, but won't be noticeable in an otherwise great looking image.

The secret to converting for good print color is to choose the source and target correctly.

If you are serious about color, buy the book "Real World Color Management" by Bruce Fraser, Chris Murphy and Fred Bunting.

http://www.amazon.com/Real-World-Color-Management-2nd/dp/0321267222/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1198178251&sr=1-1

Sadly, Bruce Fraser passed away, so the book may not go to a third edition.But you can still get the second edition and the first 5 or 6 chapters are an education in themselves.

[Lukas Engqvist]

I would convert in InDesign rather than in Photoshop, because that would generate more consistent resukts, it also allows to change to another CMYK output profile in the last minute, and leaves your pictures more flexible for cross media. I would however make sure that there is no flattening in images by opening them in photoshop and viewing with gamaut warning, and proof in output CMYK, to be able to jude that no essential colour is lost, or that yellows go green.

Check: Reds and Greens don't go flat, Blues don't go purple, and Yellows don't get unwanted contamination (cyan).

[Guest]

can you show me how to do that please

[_Gordon_Anderson_]

"There's more to all of this, of course, but that would be a good start."

Are there any articles out there that show up-to-date information regarding Color Settings for print, etc? Doing google searches brings up quite a bit, but much of it was written several years ago and refer to CS and CS2.

Thanks.

Gordon

[_Leslie_W__]

I created my file in Framemaker 7.2 and imported Black and White grayscale images, when I wrote the postscript to create a PDF everything was fine until I did the preflight only to learn that my images have converted to CMYK...These graphics need to print grayscale not CMYK. I am working from the PC and this is a very large document.

[Ramón G Castañeda]

See reply to your duplicate post in another thread.

[Guest]

It is still not clear (Marco_Ugolini) I still can not do it, please show me any print screen so that I can easily follow it. Thanks  

[Andy_Baz]

When converting to CMYK always be sure you understand what printer your job will be printed on before converting to a profile, and make sure the correct profile is used.

The most recent method and in my opinion best method (#ThankstoDavidBlatner) of leaving images RGB until outputting to correctly converted PDF in InDesign (or other such program) enables you to keep only one source file that can be used on multiple devices rather having multiple copies of the same file using different profiles, and also stops the potential to end up using incorrectly profiled files when printing.

[MissSparkles75]

What if your client is unable to get the print details from the print house or is reluctant to give you the contact details of the print house directly (goodness knows why!), how on earth do you know whether to leave the images as RGB or change them to CMYK, I am worried that if I leave the images as RGB for the print house to sort out and the print house don't think to change them to CMYK the end result will be awful?

I have this same trouble with trying to get the PDF spec from some print houses, it's like pulling teeth, I am going to have this issue with this current job too if I cannot get hold of the print house's contact details. I just want to make sure I set the artwork up as best I can for the best results.

[NB, colourmanagement]

Hi Miss Sparkles,

That’s a really difficult situation; personally, I would feel its important to explain to the commissioner that the your knowing CMYK destination [having a good icc press profile] is vital to getting good colour in print. Unless, that is, the print house will take very good care of converting your RGB to CMYK.

More here: https://www.colourmanagement.net/advice/press/

If you did send RGB files then someone down the line will HAVE to convert to CMYK, but who knows how much care they will take over this.

However, basically, it's not possible to print RGB on a print press.

If you need help with this decision, why not have a look at my posts above and that should help you to know what questions to ask.

ON balance, given the information you've supplied, I think you may have to supply the files as RGB

- otherwise [I love an analogy] it's rather like hitting a golf ball over a hill and expecting it to land in a hole you've never seen  [you may not even hit the green] - it doesn’t matter how good a golfer you are, you have to know where the ball is supposed to end up.

I hope this helps

if so, please do mark my reply as "helpful" and if you're OK now, please mark it as "correct" below, so others who have similar issues can see the solution

thanks

neil barstow, colourmanagement

[MissSparkles75]

Thanks so much Neil and Test Screen Name, I love an analogy too and yours NB describes the situation very accurately, all I have is that it's an advert going in a magazine so I have requested the printer details saying that it's imperative that I have them in order to set up the files correctly.

I will read your posts above, I was not aware that there was a more accurate method of changing an image from RGB to CMYK than to just change it in Photoshop from RGB to CMYK (Ive never been taught another way) and I want to achieve as good a print job as possible, I just hope your posts are in simple terms that I can understand as replies on here, whilst much appreciated, can get a little jargony and complicated sometimes I think.

Thanks so much for your help and your analogy.

[NB, colourmanagement]

Hi Miss Sparkles

Personally I do try very hard to avoid jargon, I can remember learning about all this subject myself, getting started back in the late 90's.

Sometimes the jargon was hell. Occasionally, though, "scientific" language is vital. I do feel it should be accompanied by explanations too where possible.

Of course, forums can be places where contributors dash off a few words and don't pay heed to the questioners possible level of knowledge. It can be hard to get that right, we volunteers here do try.

neil barstow, colourmanagement