converting RGB to CMYK - fails

what color profile are you using?

 

I don't know about the color picker, but as to vibrancy, note the difference between the RGB and CMYK color gamuts.

(That image turned out a bit bigger than I expected)

No need to convert them at all. Just print them as is. Trust me, they'll come out just fine.

Dan

Here's what happened (will try to keep it brief). 

I created some cards, realized there was a mix of rgb/cmyk and changed some of them, but they didn't look the same.  Some I left.  When I brought to the printers, they put the resulting pdf file into an adobe product and the shadows went to h*ll in a handbasket and some of the colours really lost their vibrancy. 

When I got home, I tweaked some of the colours and got the same results (was glad it wasn't my screen calibration). 

Is there an easy way to send you the colour profile, without sending you a print screen.

Thanks for input.

PS ... interesting differences on the colour picker for RBG vs CMYK. 

Cowtoon:

I now need to convert some of this stuff for print and when I convert from RGB to CMYK, the colours lose their vibrancy.

Since the color gamut for RGB is much wider than the CMYK gamut, it is not possible to print the vivid RGB colors on a CMYK printer.
There's no need to convert the colors before printing, but no matter what, you can not expect them to print correctly.
Enable "Proof colors" (little monitor icon to the right in Status Bar, and you get an impression of how the colors will look when printed, this is IF your color management settings are in order).

What do you mean by "picker"?

Cowtoon:

I have created some vector drawings for the web or electronic viewing only.  I now need to convert some of this stuff for print and when I convert from RGB to CMYK, the colours lose their vibrancy.  and when I'm converting, I no longer have the picker to work with.

Can someone help? ... please and thanks.

Thanks.

Since RGB has 16.8 millions colors and CMYK only 64.000, the difference is easy to understand. btw a correct color profile will produce a better change, according with the material and system of printing. But the brilliant and luminous colors of RGB will loose bright when you convert to CMYK

 

Terremoto:

No need to convert them at all. Just print them as is. Trust me, they'll come out just fine.

Dan

This is an dangerous advice. Some RIP can convert from RGB to CMYK, suing their internal color profiles, but not all do it, and not all have this option enabled. On almost all case, if you send a, RGB image the result will be a pale image, without bright, color and contrast...If you are not really sure that the RIP has this feature, never send an RGB image. On 99% of the time the result will be wrong

Ariel:

Since RGB has 16.8 millions colors and CMYK only 64.000, the difference is easy to understand.

This is not correct.
It has nothing to do with the available number of colors, but instead the fact that many RGB colors are outside of the CMYK gamut (see picture in Bob's post).

Every pixel in a true color image has 256 possible values for each of it's red, green or blue components (in the RGB model) or cyan, magenta, yellow and black (in the CMYK model).

This means that a 24 bit (3 x 8 bit) RGB image can have 256 x 256 x 256 possible combinations or 16,777,216 possible colors.

Each pixel in a 32-bit (4 x 8 bit) CMYK image is one of 256 x 256 x 256 possible colors x 256 variations of black. This is an awful lot of colors but in Draw we are limited to 100 steps instead of 256, which makes the number of possible combinations smaller (still though; 100,000,000 colors, theoretically).
The color space is the same though, but as mentioned, much smaller than the RGB space anyway.

 

The colour picker is a tool that allows you to pick any colour on the screen (and outside), but if the colour it lands on (for picking) is already RGB, it will take is as, even though you started out with CMYK as your preference.  The picker tool looks like an an eye-dropper.  I've never run into this problem before. 

Ariel:

Terremoto:

No need to convert them at all. Just print them as is. Trust me, they'll come out just fine.

Dan

This is an dangerous advice. Some RIP can convert from RGB to CMYK, suing their internal color profiles, but not all do it, and not all have this option enabled. On almost all case, if you send a, RGB image the result will be a pale image, without bright, color and contrast...If you are not really sure that the RIP has this feature, never send an RGB image. On 99% of the time the result will be wrong

 

My experience comes from the signmaking industry and outputting to wide format digital printers. I've used Onyx, VersaWorks, Wasatch, and I've played around with the demo version of Caldera. All of them accept RGB and provide excellent output on all the Rolands, Mimakis, Mutohs that I've run.

When I first started using a wide format digital printer I had two days with the fellow I was replacing. He showed me the color charts they'd printed out and how to use them to match colors. He tried to explain to me how you had to tweak this color and that color and that he always had trouble getting a nice rich black. He did all his design work in CMYK and was a "Graphic Design Graduate" from a large technical school here in Canada. At the time I assumed he must have known what he was talking about.

I struggled with getting the colors to come out the way I expected they should so I started doing a bit of research into setting up a proper ICC compliant workflow. First thing I discovered was that CMYK isn't really a standard. Sure, you have a bunch of CMYK color profiles available with a stock install of CorelDraw and here in North America U.S. Web Coated (Swop) v2 tends to be the default. Fair enough. The values that show up for any particular CMYK color you pick from the CorelDraw CMYK palette should theoretically map to the U.S. Web Coated (Swop) v2 profile. To map straight across the printer / RIP itself needs to set to U.S. Web Coated (Swop) v2. Trouble is that the ink-sets for the various CMYK printers out there vary a lot. Roland's Yellow is different than HP's and they're more than likely different than Mimaki's.

After a bunch of reading and head scratching I finally came to the conclusion that the workflow needed to be linearized. Calibrate the monitor with the Eye1 we have here. Create a proper profile for the printer using the data collected by the Eye1 from the color output of the digital printer. Now I've got those two synced up.

Talked to a bunch of color management gurus and they all said do your designing in sRGB for the following reasons:

• Your graphics are ready for web use should that be required.
• Your graphics are ready for desktop inkjet printers should that be required.
• Your graphics are ready for 6, 8, or more colors in case you decide to upgrade your printer down the road. (Finally something that Foster and I agree on.)
• The RIP's doing all the hard work by taking the sRGB data, which is device dependent, mapping it to LAB which is device independent, and then setting the ink levels (CMYK) which again is device dependent. (No unnecessary conversions or manual tweaking.)

So basically I've done it both ways as well as just crossing my fingers and winging it. Linearizing the equipment I use with the Eye1 and designing in sRGB has saved me a ton of time, a bunch of hair pulling and generally made my life a whole lot simpler and my output considerably more consistent and predictable.

That's why I'm sticking to my guns on designing in RGB.

Dan

Terremoto:

 My experience comes from the signmaking industry and outputting to wide format digital printers. I've used Onyx, VersaWorks, Wasatch, and I've played around with the demo version of Caldera. All of them accept RGB and provide excellent output on all the Rolands, Mimakis, Mutohs that I've run. 

OK, signmaking has their own workflow, and I know it's better to use RGB (I used Versaworks for years), but for offset printing is totally different, and if you send a, RGB image is very dangerous

 

Ariel:

OK, signmaking has their own workflow, and I know it's better to use RGB (I used Versaworks for years), but for offset printing is totally different, and if you send a, RGB image is very dangerous

I didn't realize that. I need to study up on that some more but we don't send much out for offset printing.

Color management is a complicated subject so it's interesting to learn out how it's implemented in the various workflows that Node Jockeys run CorelDraw through.

For starters (maybe this should be the beginning of a new thread). What CMYK color profile do you use and what CorelDraw CMYK palette do you use to put together a design for output to an offset printer? I'ld like to learn more about this.

Dan

I'll not go into a RGB vs CMYK debate here too. For those interested, here's my opinion. :-)

One thing though:

Terremoto:

Trouble is that the ink-sets for the various CMYK printers out there vary a lot. Roland's Yellow is different than HP's and they're more than likely different than Mimaki's.

That's one reason all printer manufacturers have specific output color profiles for the combination printer, ink type and printing media.

Cowtoon:

The colour picker is a tool that allows you to pick any colour on the screen (and outside), but if the colour it lands on (for picking) is already RGB, it will take is as, even though you started out with CMYK as your preference.

My guess was you meant that one. :-)
The color picker reads the information from the object you hover over, and since Draw can handle both RGB and CMYK colors in the same document, it will show RGB or CMYK accordingly.
It can also select colors from the UI and they'll be RGB of course.

One exception to the rule (there may be several but this one I know) is powerclipped objects, which will take the color model from the fill of the container, or if there's no fill; from the default color model of the document.

Yes ... and they've made the colour picker smarter which, is mostly a good thing. 

btw ... There's some interesting reading in the responses here,   I'm not all knowing, esp. when it comes to print.  My experience is limited and there's always been at least one thing that challenges the outcome.

At this point in time, the no. of prints don't warrant offset, however, the printers use a printer that uses CMYK, so I'm still kind-a hooped.  Many of the colours as mentioned earlier, had a washed out look.  Moving foward, I'd like to prevent this.   From what I've read, I don't seem to have the full selection of colours, using CMYK as I do with RGB. 

Do you think it would help (from the printer's perspective) to save as an illustrator file).  There were also issues with CD's shadows, which had to be corrected.  Fortunately, I was charged for that bit of tweaking.

Perhaps there's a goofy (yet useful) little tool out there that will give me the cmyk values for a colour I chose (assuming it's available in the cmyk spectrum).

Thanks.