Best Practice RGB to CMYK ?

Can some of you guys that work with print, point me at a decent link for a best practice workflow going from RGB to CMYK? This is for outputting a large graphic that contains a number of RGB colour photographs, for imput into Indesign, and export to PDF for print in a newspaper advert. I have the paper's requirements. The job in question is not colour critical, but I would like to feel better informed.

Trevor,
CMYK is a darned narrow color mode, even narrower than the sRGB profile.
Of course you're bound to see some of your RGB colors just die in your image during the conversion. That is the nature of the beast, and that's where soft-proofing with the target profile comes to the rescue, partially, by letting you fine tune the colors to compensate (somewhat).
Just look at all those greens, blues and reds outside of the CMYK spectrum.

Similar Messages

Best results when changing RGB to CMYK

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

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=UTF 8&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.

Placing Images (Screen Caps) for Callouts - Best Practice?

Illustrator CS6, Windows 7
I'm placing screen captures (screen images from software) in my artwork files to add callouts and create illustrations for a user manual.
The machine I'm capturing on has a screen resolution set at 1920 x 1080 (required for software). I'm using Snagit and capturing the screens, saving files, then placing in Illustrator. I've been using images minimum 300 dpi and never upsizing in Illustrator. Still I think my results could be better.
In the past I've used .jpg as my export filetype for placing into Illustrator. But, recent reads of postings in this community lead me to believe my practice might be flawed.
Question: What is considered best practice for placing images from screen capture (or any source) in Illustrator? What file type from capture will get me the clearest and most adaptable results?
My Illustrator file color mode is CMYK and my other art and callouts supporting the screen cap are working great.
I'm creating the artwork for import to Framemaker and creating a PDF for online and print.

What I mean is; what is the user looking at, and what are you training on?
For example, if the application involves medical imaging, and part of your documentation covers something like evaluating medical images in the application, that would probably be a far more color-critical scenario than an application in which the user just views and manipulates data.
Generally, you don't need anything like 300 PPI for screen captures in software documentation. The whole intent is for the image to look like the screen you are documenting, which is something like 72 or 96 PPI at actual size. You might downscale a screen capture as much as 50%, but at that size, the reader is viewing the application's text (including menus, etc.) at half the size as viewed in the application, which is assumed to be sized for comfortable reading. Sharpness is good. You don't want the images to become blurred in pursuit of completely needless "resolution."
Also generally speaking, software screenshots are not usually color-critical. Placing (even pasting from SnagIt) directly into the page layout app is usually just fine. PostScript knows how to separate RGB images. Such things have been done since long before anyone sweated blood over "color management." Assuming your application interface is not using garish color (which would be poor interface design; it's tiring), I dare say the conversion of RGB screenshots to CMYK at the imagesetter or press would be fine.
How is the manual going to be printed? Unless you're talking about a large press runs, nowadays software documentation (subject to frequent updates) is often printed on on-demand presses (think glorified digital color copiers), not sheetfed presses. With software documentation, you're not usually talking coffee-table collector's books. (The exception would be something like a book on color-correction in Photoshop; thus my first question.)
I routinely paste screenshots from SnagIt directly into InDesign pages to document software applications, and add the callouts in InDesign. Only when I need some special graphics (swooping arrows, etc.) do I assemble the callouts to the screenshots in Illustrator; and even when I do that, I also typically paste the SnagIt captures directly in to AI.
Keeping your callouts native to the page layout program also better facilitates language translation, when you have to outsource that.
JET

Smart Objects: RGB inside CMYK

Just two days before completing a two week job the client decided (still dont know why) the job had to be delivered with open layers on CMYK.
After two weaks and 6 jobs and hundred of layers latter had almost all work done..in RGB. I started to panic thinking of the time I would waste just appling curves,levels,etc... to every layer,while keeping things open if they wanted last minute changes.
Thats when it struck me..why not leaving everything as it was (RGB) and convert it to a smart object and then convert the parrent file to CMYK?
I has suprised how it works just fine.In the end the client agreed it was better to keep things as they were,but it sounds a really nice possibility and to some extend makes perfect sense as one would retain the full Gamut of RGB (AdobeRGB or any other) and could convert to proper CMYK acording to needs.
As anyone experienced this?

Mark -
There are a few gross errors in Photoshop that are seen as bugs, but go uncorrected for years due to the amount of work needed to fix them - not to mention - get it worked into the correction cycle in development. Marketing is steering the train. Go think about that oxymoron for a few weeks...
;o)
One major problem is the conundrum of being able to open an untagged file, assign a color space, then look at it. That in itself is counter intuitive and basically a HUGE hole in the application with respect to color management. With the new proposed architecture of creating the entire application Smart Photoshop - You not only eliminate this issue, but also have created a new and improved workflow - integrating source color images into the working space, tagged or untagged, with consistency for all. Adobe products are now far and wide enough to have the majority rule, so why not capitalize on it and implement a global workflow. This logic works for many industries Adobe serves. From 2d, 3d to motion video, cell phone, bio medical, and who knows what's next. It's image history preservation in its simple form.
In English, whittle down 9 options to 2 for color policies and change the logic between RGB and CMYK file handling. Convert to working space. Have the working space 32 bit Pro Photo RGB. Files flow into it as well as color space conversions. Now remember, this is a choice feature and not a force fit. It's a marketing born inception that caters to the masses for best practice. If you want to work outside that environment, its your choice, but it's not advisable unless you are resurrecting trash, re-assigning really bad pictures, or it does not work for your requirement and a new additional per-dim needs to be created. I'm offering a choice. Two choices to be specific. Road or off road travel. For here now, and tomorrow. It's a creature of growth, just like the implementation of Smart Objects that has morphed more possibilities as well as options. But Smart Objects is a representation of Adobe's expanded free for all mentality to push the envelope of development for market share. My advice is to back on the whizz bang wow factor and get some damn control of the features grained in deep rooted experience from power users....
Smart Photoshop is needed because users are not getting it Gentleman and Ladies. Expecting most users to become geeks is not going to happen. It's a given from a marketing stand point, but they refuse to see how to address it for one reason or another. Maybe too busy dealing with the company merge and product integration. Im pretty sure its quite an undertaking, but its time to make the best - better....
I remember Bruce Fraser talking about Chris and Thomas wanting 12 ish choices for color policies fearing too much restrain for growth. Thank you Bruce for 9, but my friend, we need even less.... Smart Photoshop gives 2 choices. Structure or Chaos. Right now we only have chaos. My vote is to have uniformity with very little user understanding and awareness. That's good implementation. The software has to become intelligent people.....
I'm game. Who has balls here?
nice to see ur pair Rich.

What are the Best Practices for Optimizing Images in InDesign Files

Is there a best practice for using images InDesign to optimize the document before converting to a PDF? Specifically, what I'm asking is, will the PDF file compress better if the images are cropped prior to placing them in Indesign? I'd like to know the answer for both creating PDF files for printing using images that are 300dpi and for creating PDF files for online delivery using images that are 72dpi. I have an employee that insists images need to be cropped to actual dimensions before placing in the InDesign document. I've never done it that way and believe that her recommended process is way too time consuming and leaves you with no leeway to tweak your page design since the images are tightly cropped.

As for absolute cropping, I agree with your stance. Until the layout is fixed, preserving your ability to easily manipulate photo size and positioning is key.
Some clever image management methods have been described in the discussion forums, and one that appealed most to me was the use of duplicate linked image folders. Having a high-res (CMYK) folder and a low-res (RGB) folder to switch between for different output enables you to use both to your advantage. Use the low-res images for layout, for internal proofing, and for EPUB/online PDF/HTML output. Then it's simply a quick switch to the high-res image folder for print purposes. You can easily prepare the alternate collection of images with a Photoshop batch convert script or with the Photoshop Image Processor. Save your presets!

Why do the relative values of RGB and CMYK change when switching between Photoshop and InDesign?

I'm trying to put together a Colour Guide for my company's brand guidelines.
I initially worked from InDesign and wrote down all the H, RGB, and CMYK values that I got when I eye-dropped my original colour palette.
However when I put the same RGB values into Photoshop- I am given a (slightly) different set of CMYK numbers from those that I had originally documented in InDesign.
Why is this???

Jamie,
in Photoshop go to Edit > Color Settings and choose your parameters:
For RGB: sRGB or AdobeRGB (1998)
For CMYK: the process as recommended by your printer (person, company)
For offset printing this is here ISOCoated-v2-eci and elsewhere for instance SWOP.
For digital printing you should ask the company as well.
For Grayscale: Gray Gamma 2.2
For Spot: probably irrelevant in the moment. Dot Gain 20%
Everything as shown here:
For your application I've modified my settings a little, therefore we can see top left 'unsynchronized'.
In InDesign do practically the same, but there are no settings for Grayscale.
You'll find for any topic explanations if you move to by mouse (position the pointer over ...).
The field 'Settings' shows not 'Custom' but the file name of a configuration which had been previously saved
and then loaded (buttons top right).
Further explanations on request. It would be quite useless to explain everything now at the same time.
The colors will be wrong if the settings are not synchronized. Above they are explicitly synchronized.
Because Bridge was not used, the system considers them as 'not synchronized', which doesn't matter.
Best regards --Gernot Hoffmann

Converting from RGB to CMYK makes the image dull. How do I fix?

I have an image that has a really bright vibrant blue in it. When I convert it from RGB to CMYK, it gets pretty dull. Is there a "trick" or something to do to a file after converting to CMYK to bring back some of it's vibrancy?

Sharingene wrote:
Question on workflow... so do I convert my sRGB to CMYK, work to fix different color issues using some of the methods above, then what? Where does the printer's profile come into play during all of this? UPrint told me for offset printing they use US Web-coated SWOP v.2. Just not sure what to do with this information
Whenever you convert, you're always converting from the source color space to the destination color space.
In this case, your source color space is sRGB, because that's the color space your file is in.
Your printer told you that the CMYK profile they use is USWebCoatedSWOPv2, so that's the destination color space you want to convert to. You can consider that the printer's profile.
So, how to convert?
There are two ways.
First, you could go to Image > Mode > CMYK. Easy, but maybe not right.
That method will convert to whatever defaults are set in Photoshop's Color Settings (Edit > Color Settings). Check out your Color Settings. If they are set to any of the North America presets, you're in good shape, because the CMYK default is USWebCoatedSWOPv2. However, let's say that the printer told you to use Web Coated SWOP 2006 Grade 3. Then you need to take a different approach...
Second way: go to Edit > Convert to Profile...
In the dialog that appears, click on the Destination pop-up and scroll to find the appropriate profile.
Click OK. Conversion done.
This is a more deliberate method that also gives you control over Rendering Intent. (That's another discussion. For now, use Relative.)
-I guess it's used in soft proofing but sure how all this works. If I soft proof and it's still not looking right, am I able to edit with their profile turned on some how?
A soft proof is an on-screen simulation of what your color will look like once you do the conversion. In your case, you would turn on soft-proof (command-Y) while still in sRGB to simulate the look of the CMYK color space.
To select the color space to simulate, go to View > Proof Setup.
Click on Custom...
Click on the Device to Simulate popup.
Scroll to find the destination color space.
Then when you hit command-Y, you'll see a soft proof of that color space.
Best practices suggest that you do the bulk of your color correction while still in RGB, but with soft proof on.
Also, should I get a profile for the paper I'm using as well?
That's what the printer's profile is.
Although I've read somewhere it's hard to have your monitor replicate paper because monitors are so bright....
Not exactly. The challenge in getting a visual match between monitor and proof/print is based on the fact that a monitor is emissive (i.e., it's a light source) and a print is reflective (i.e., it only reflects light that's hitting it.) However, in a proper, well controlled editing environment, it's possible to get a shockingly close match between monitor and proof/print. All the variables are controllable.
The bottom line with all of this is to be able to get accurate, predictable color on press (or out of your inkjet) based on what you see on screen. It can be done; I do it every day. It just takes some study and rigorous process control.
I humbly suggest that you check out my book.
Good luck!
HTH,
Rick
Rick McCleary
author, CMYK 2.0: A Cooperative Workflow for Photographers, Designers, and Printers
Peachpit Press

Need Info on RGB to CMYK

Hi,
I am new to Illustrator (CS5) and not fully comfortable with RGB vs CMYK. For instance, I created a logo for use on the web using Document Color Mode: RGB where my background color in RGB is 0, 0, 130. When I create a Print document using Document Color Mode: CMYK and copy the logo into the print document, it converts that background color to CMYK (C:100, M:98, Y:16 K:18) where the RGB is now (44, 45, 111).
Is there a way to get a closer match to the original RGB color 0, 0, 130? When the specifications for the print advertisement says images must be in CMYK, I hope I am accomplishing this by using the Print Document Color Mode of CMYK vs RGB? I feel somewhat ignorant on utilizing the RGB vs CMYK color modes and if anyone can give me a tip on what techniques they use to get a closer match of colors for RGB to CMYK or vice versa, I would love to hear it.
Thank you,
Keith

Keith,
First, be aware that you have posted to the Photoshop forum, not the Illustrator forum. The general concepts of color and color management are the same across the spectrum of digital imaging. However, its implementation is slightly different from application to application, so you may also want to post your question to the Illlustrator forum.
[EDIT: Brain fart on my part... This is the color management forum, NOT the Photoshop forum, so you are in the right place! (I spend most of my time in the Photoshop forum; I lost track of where I was...)]
That said, you're running up against a general concept: color gamut.
The color you've spec'd in your RGB file (0/0/130 - and we'll assume for now that it's in the sRGB color space) is outside the gamut of every CMYK color space. That means that the RGB color you see can not be reproduced using a mix of the four CMYK process colors (cyan, magenta, yellow, black). When converting to CMYK, the software picks the closest color that is within the gamut of the CMYK space, hence the color shift.
When you're designing for CMYK, it's best to work in soft-proof mode which allows you to see a pretty close approximation of what your colors will look like in the final color output space - in your case, CMYK.
In Photoshop, to turn on soft-proof, go to View > Proof Setup> Custom... and choose the CMYK output space that matches the press conditions you are designing for.
There are books written about this, but hopefully this short answer points you in the right direction.
Message was edited by: Rick McCleary

RGB to CMYK to commercial printer

We are using CS2 InDesign and Photoshop 7 on a PC. I am putting together two
large books. One insert section of the first book has color photos. I have
to prepare these color photos for a printer located in China. They want all
images to be CMYK .tiff.
I have an assortment of about 100 images from various sources around the
world, there are .tif, .jpg. .bmp, and .psd. All of them appear to be RGB.
There are images with: 1) no color profile, 2) sRGB IE60966-2.1, and Adobe
RGB 1998. Do all images need to have the same RGB color profile before
converting to CMYK?
I have been converting all of these to .tif (and using a single dpi/pixel
resolution for
all images).
Do I just select/save as color mode CMYK? Or are there special
settings/profiles I need to know about. Is there anything special for China?
The printer's English is not that clear . I was hoping that someone in this
group would be familiar with RGB to CMYK conversion.
Also, it appears that the final PDF pages (with embedded Tiff images) will
be very large. The first complete book for this project (there are two
books) looks like it will be about 20GB. The second book looks like it could
be 12GB. Both books together equal about 1,000 pages and have about 1,000
images. 90% of the images are grayscale. What are the current technologies
for sending large projects like this to a printer?
Thanks
ps, the Photoshop group suggested that I write to this group.

Tech....
In the conversions, are you referring to conversions of B&W or color images? I'll assume color for the moment.
Assuming your monitor is properly calibrated, and assuming you are viewing your color images on your monitor, your conversions should keep "in gamut" colors the same. You will, however, probably see some loss of dynamic range, color, and saturation as you enter CMYK. If the color and dynamic range of the original is all within the destination CMYK gamut, you should see very little, if any, shift. The sad fact is that CMYK on press has limited dynamic range and color, especially compared to a bright monitor. This is generally true, though CMYK can print some colors that lie outside the typical monitor's gamut.
If you have a brightly colored original in RGB mode, then you should experiment with both perceptual and relative colorimetric rendering to see which one looks best. This is an image by image thing. Relative colorimetric will reproduce all "in gamut colors" as accurately as possible, then will take out of gamut colors and bring them to the closest printable color. This can cause loss of detail and 'piling up of colors' as you near the boundaries of the image's color gamut in the destination CMYK space. Perceptual scales ALL colors and preserves the relationships between colors, which sacrifices color accuracy and saturation, but sometimes looks more natural, especially if there are a LOT of out of gamut colors. Pick whichever ones looks best overall.
Then, once in CMYK, make minor curves adjustments to tweak if for CMYK. Just be careful not to push it too far, especially in the deep shadows, since you may push beyond the ink limit of the press. For example, if you convert to US Web Coated SWOP v2, the ink limits are set at 300 total. If you drastically darken the shadow areas, you could end up with an ink limit of 320, 330, 350, etc. Knowing the ink limit of the press will help you stay within those limits. Final tweaking in CMYK is usually a good thing.
How did you determine that the images were dull with too much magenta? Did you print a proof on a calibrated printer, or is this just your screen display? Or is this from a printed image off the press? I have a well calibrated monitor and accurate custom profiles for my inkjet. If I am sending a job to a press that supposedly prints to US Web Coated SWOP, I can proof that file on my inkjet and get a very good match. We need more information to know exactly what you are doing and how you are assessing your images.
Normally, I do the conversion in Photoshop, using the rendering intent that looks best. Then I tweak the image in CMYK to get it looking its best. I usually have the press profile, but sometimes work with a standard profile if no custom profile is available. I leave the image tagged with my conversion profile. Then, I usually place these images into InDesign, with the profile intact (color management turned on in InDesign). I right click on the placed image to be sure that the profile and rendering intent are set to what I want. Then, I can either supply the InDesign file to the printer, or convert to PDF (leave color unchanged) and make sure that all profiles are included. InDesign should export each image to the PDF properly, along with profile and intent. I have never sent to job to press using Photoshop...only InDesign or Illustrator.
BTW, rendering intent is only used when getting an image from one color space to another, such as a conversion from RGB to CMYK. You do that, choosing the one that looks the best. Once it is in the destination CMYK space, rendering intent is no longer needed, since all the colors and tones have already been remapped into the final space. Rendering intent is just used to help us handle those out of gamut colors.
Hope this helps.
Lou

How to make a script to convert RGB to CMYK as black 100%?

Hi guy
my customer sent me a book (144 pages) for print but all of them are RGB and Tiff, she scan them. there are on the page some texts and pictures. The text are R=30 G=30 B=30.I think if I can make a script I will do it very soon to black 100%, but unfortunately I dont know anything to make script
anybody can help me ?anybody can make it for me ?

We need to know some more information.
1. The book consists of 144 pages, and each page is in fact an RGB image in TIFF format.
    Correct?
    That means, the text is already rasterized, but with low resolution (no more than 300ppi).
    A very bad starting point, in my humble opinion. For offset printing this is not acceptable.
2. Is the printing process offset printing or by digital printing?
Nevertheless we may think about a conversion of these images into CMYK K-only (one plate
per page) .
a) Increase contrast until R=G=B=0 for text.
b) Convert each image into Grayscale, using a so-called Black-Ink-Profile, for instance
    Black-Ink-ISOCoated-v2-eci (can be explained later)
c) Make empty CMYK image, here for ISOCoated-v2-eci, and paste the Grayscale into the
    K-channel. All further handling happens as CMYK file for the process ISOCoated-v2-eci.
    Void plates CMY don't matter.
    Post #12 here:
    Re: Colour shift (from CMYK = 0 0 0 20 to Grayscale K = 22 !)
All this can be done by an action (I hope so...).
Much better would be a new start by InDesign with typographical text (K-only vector instead of raster)
with images in RGB or CMYK, taking into account the intended process.
Note: Photoshop can deliver vector text, if exported as PDF.
Best regards --Gernot Hoffmann

Why does Illustrator automatically change RGB and CMYK values

Hi, I am struggling to understand why Illustrator is changing the values inside the RGB and CMYK boxes. I am also not sure of the exact relationship between these values. Essentially, it appears that if you set the Document Color Mode to RGB, it leaves the RGB values that you type in alone. If you set the Document Color Mode to CMYK, it leaves the CMYK values alone.
But as soon as you change the Color Mode, it automatically modifies the values. So if you were in RGB mode and you set some RGB values, it changes those RGB values when you switch to CMYK mode. And vice versa.
I had thought that the CMYK palette was a subset of the RGB palette. It would make sense to me if it did this when I switched from RGB to CMYK mode, but it doesn't make sense to me why it does this when I switch from CMYK to RGB mode.
The other thing I am confused about is the relationship of the values in the RGB boxes to the values in the CMYK boxes. I would have thought that the relationship between them would be static. Actually, it is not. When I am in CMYK mode and I enter a CMYK value of 90 16 0 0, the RGB values become 0 158 222. But when I switch over to RGB mode, the RGB values of 0 158 222 result in CMYK values of 75 23 0 0.
Very confusing.
Thanks in advance if you can explain this behavior!
Best Regards,
Z.

Color management.
Hi, I am struggling to understand why Illustrator is changing the values inside the RGB and CMYK boxes. I am also not sure of the exact relationship between these values. Essentially, it appears that if you set the Document Color Mode to RGB, it leaves the RGB values that you type in alone. If you set the Document Color Mode to CMYK, it leaves the CMYK values alone.
An Ai document can be either RGB or CMYK. The colors follow the document color mode and thus are converted immediately if they don't match.
But as soon as you change the Color Mode, it automatically modifies the values. So if you were in RGB mode and you set some RGB values, it changes those RGB values when you switch to CMYK mode. And vice versa.
Same reason.
I had thought that the CMYK palette was a subset of the RGB palette. It would make sense to me if it did this when I switched from RGB to CMYK mode, but it doesn't make sense to me why it does this when I switch from CMYK to RGB mode.
It's not. CMYK color spaces (there are more than just one) are normally smaller than RGB color spaces, but they aren't a "subset".
The other thing I am confused about is the relationship of the values in the RGB boxes to the values in the CMYK boxes. I would have thought that the relationship between them would be static. Actually, it is not. When I am in CMYK mode and I enter a CMYK value of 90 16 0 0, the RGB values become 0 158 222. But when I switch over to RGB mode, the RGB values of 0 158 222 result in CMYK values of 75 23 0 0.
When Illustrator converts the colors, it uses color management: the profiles you set up and the methods you set up. After converting it forgets the color that used to be. When converting "back", it uses color management again.
When you convert an very bright RGB color, it be out of the CMYK gamut. So it get's converted to the closest possbile CMYK color (which might still be far away from the original color. But it's not possible to convert it "back" to the bright one unless you just revert the conversion (by Cmd/Ctrl + Z).

RGB or CMYK colour formatting for iPhoto Albums printing.

Hi.
I'm putting my first iPhoto Album together. Info given from Apple about what colour format to use for your photos, says to use RGB. While this is corrcet for digital monitors and screens. Mass printing uses CMYK. Any images supplied to a printers in RGB will colour shift when printed in CMYK. No matter what a printer tells you, these colour shifts can be very noticable. I'm an Advertsing Art Director and I've seen the shift that happens.
I will be checking/colour correting all photos submitted to the iPhoto Album with Adobe Photoshop. And many will very probably undergo some corrections. Be it through levels, curves, hue/saturation, etc. Nothing to anything near an excessive level, but enough to make obvious improvements.
So I will then be faced with the choice of whether to save the images out in RGB or CMYK.
Can someone with some technique knowledge, from the iPhoto team, tell me/reasure me why RGB has been specified? And if CMYK wouldn't actually be a preferable colour format to supply in, considering you'll be printing them in CMYK.
Many Thanks, Jim.

You're absolutely correct. I was referring to notes make a number of years ago in regards to iPhoto 5 and that RGB was recommended for both books and prints.
I was confusing CMYK with Grayscale with Dot Gain 20% profile when stating iPhoto didn't support it which it didn't fully support until iPhoto 9.
In fact I just ran a test with iPhoto 6, 7 and 8 with a CMYK AND GrayScale files with the following results:
iPhoto 6 (06): wouldn't import CMYK but did GrayScale. The grayscale file would only display as a black thumbnail and negative full image. If the DotGain 20% profile was stipped from it the iamge would dispaly normally.
iPhoto 7 (08): wouldn't import CMYK but did GrayScale. The grayscale file would only display as a black thumbnail and negative full image. If the DotGain 20% profile was stipped from it the iamge would dispaly normally.
iPhoto 8 (09): neither file would import which is surprising:
iPhoto 9.2.3 (11): both imported and viewed normally.
iPhoto 9.4 (11): both imported and viewed normally.
In Oct, 2007 I got an email from Apple support with the following:
Also as iphoto makes a pdf of the book and then uploads it to keep the size down, it doesn't matter if the pics are RGB or CMYK as a pdf is a closed file. But since it is going through prinergy it has an RGB checker so this most be switched off. It is how the software in prinergy handle's it that causes the washed out affect as it takes the Red Green Blue colours and tries to convert to Cyan Magenta Yellow Black. Now the colour spectrum in printing between rgb and cmyk is quite different looking at a colour wheel will show you. The best way i can describe it is if you have a pantone book which has spot on one side and process on the other you can see a colour difference. Or if you use quark open up the colours and again switch between process and spot.
BUT ONLY CONVERT PICS TO CMYK IF YOU ONLY INTEND TO ORDER BOOKS. IF YOU INTEND TO ORDER PRINTS IT WILL NEED TO BE RGB.
Here's how i see it:
1. Apple doesn't want 2 different versions of the pics floating about as running CMYK through a photomachine (as prints you would order in the high street) will not print correctly.
2. RGb's going through a CMYK press using prinergy will attempt to convert and produce the washed out effect, or yellowing effect BUT will still print.
So it will use the 2nd option as it will still produce prints normally and books with a slightly washed out effect. Now to most people in the high street, who will notice a difference?
I have just received my latest book saved as CMYK pics in tiff format and no washed out effect. What i will say is The quality if still not as good as a print. Now we use a docucolour 5252 at work and the colour quality is better. I wonder how often the machine is calibrated and what colour curve it is set to?
However, I am unable to import a CMYK file in any iPhoto version until iPhoto 9. Go figure.
Thanks for the feedback. Hadn't addressed this particular subject in quite a long time.

Once again: RGB to CMYK using Acrobat?

I received a lot of photographs in RGB (my color space for RGB is default to preserves embedded profiles) and make a proof in IDCS4:
1) I converted that batch to CMYK using PDFX-1a/2001
2) I converted to CMYK in Photoshop and later distilled
And the result is different. More darker photographs were obtained with the first step. Blacks were different.
How to avoid the previous conversion in Photoshop and obtain better results (or those obtained in step 2) directly with Acrobat?

mariana pineda wrote:
I received a lot of photographs in RGB (my color space for RGB is default to preserves embedded profiles) and make a proof in IDCS4:
1) I converted that batch to CMYK using PDFX-1a/2001
2) I converted to CMYK in Photoshop and later distilled
I'm a little confused here. With 1, you placed all RGB into InDesign, then exported PDF/X-1a from InDesign. With 2, you converted in Photoshop, placed in InDesign, output post script and distilled. Is that correct?
Neither one involved an Acrobat color conversion. 1, the conversion is done by InDesign. 2, the conversion is done in Photoshop.
Ideally, 1 is the best option. Place all RGB images into InDesign. Output PDF/X-1a, you end up with a CMYK PDF.
To ensure you achieve the same conversion that way that you would have in Photoshop, first go to Edit: Color Settings in Photoshop. Make sure Preserve Embedded profiles is on, and note the CMYK working space. The behavior should be (if you were to do the conversion in Photoshop): open the RGB, preserving the embedded profile. Mode: CMYK will move the image to your working CMYK color space.
Now go to InDesign. Open the document in question. Edit: Assign profiles, and note the RGB and CMYK. Make sure the CMYK matches what you saw in Photoshop.
Now go to the Links panel. Check the ICC profiles for the placed RGB. None of them should say Document RGB, let me know if they do.
Now when you export PDF/X-1a, in the destination color select Document CMYK. The conversion should match what you would get in Photoshop.

RGB to CMYK without losing quality

How can I convert a photoshop file, which is in RGB, into CMYK image mode without losing quality?
Whenever I try to convert the image mode, it totally changes the colors making it damn ugly. I want the brochure to be printed and for that it should be in CMYK format.
Kindly help me. Its urgent.
Thanks in advance.
Regards,
Snehal Masne

Snehal,
A lot depends on the particular colors you're using in RGB, what sort of CMYK printer or press you're using and just how you're actually converting to CMYK. Most images print just fine in CMYK, as can be seen by the many thousands that print every day in magazines and newspapers around the world. CMYK's weakest areas are bright saturated blues, which will always print like crap because the inks just cannot print those colors. You haven't told anyone exactly why your conversions look like crap, only that they do. If you posted an example, more specific help could be given, but the bottom line is that there are always going to be some compromises going to press and you, as the designer, have to take those possibilities into account when doing your design. You can also trick the viewer's eyes into thinking the image is more saturated than it really is by intelligent use of color contrasts in images and designs. For instance, using a bright yellow, something that presses print quite well, next to the best blue you can print, will make that blue appear bluer and more saturated than it really is. Of course, if you need exact and specific color matches, you can always go to additional spot color plates using Pantone or other color inks, at an added cost in both money and complexity.
Entire books have been written on this subject, and for good reason.

Having troubles converting RGB to CMYK

@Hi guys
I having massive issues with converting my business logo form RGB to CMYK. I need to place this logo on my business card ready for printing. I created the logo in RGB format to start of with, but it keeps coming out darker and abit grayscaled
once the conversation is set. Can anyone help me out with this issue, and if so, can you also provide the steps in how to resolve this issue for future references. Im using Adobe Photoshop CS5 for this execise. I can also provide the actual image attached below as the second image,.

These bright pink and purple colours are obviously way out of gamut so they convert badly to CMYK. Exactly how they convert depends on what colour profile you are using
It will probably be best to either rework the design using mixtures of cyan and magenta only or else use mixtures of Pantone colours.
The Pantone solution will only work for offset printing but is no use for a home printer.
Read up on colour management like Mylenium says and learn to think in terms of inks rather than screen colours.

Best Practice RGB to CMYK ?

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